How to install sheet piling fencing for pits with your own hands. Sheet piling fencing of pits: technology, methods, price calculation Installation of sheet piles with retraction technology

Sheet piling is used to strengthen and harden slopes, pits, engineering or hydraulic structures. In essence, it is a durable artificial wall, which prevents possible soil movement. It can withstand heavy loads and is not negatively affected by moisture, temperature changes, and so on. Widely used near various water areas to protect buildings from flooding.

If it is necessary to dig a pit on unstable soils, then sheet piling will protect against possible soil displacement

What is fencing used for?

During the construction of buildings on uneven or unstable soils, collapse of the slope or walls of the pit, soil shifts, and penetration of groundwater into the construction site may occur, which can damage neighboring buildings. To protect workers, equipment and construction site sheet pile fencing is used. They are indispensable in cases where it is necessary to strengthen the soil, especially near any bodies of water, in order to protect objects from the following situations:

erosion shores;

flushes and rock collapse;

siltation and shallowing;

collapse coastal slope.

provide protection from ground movement.

All such phenomena can be prevented in advance and various buildings can be protected using sheet piles. This technology is considered one of the best due to its simplicity and efficiency. Installation of tongue and grooves takes a minimum of time, and the fence itself is different high efficiency, strength, resistance to any type of load (tension, bending, statistics). The cost of constructing a wall is lower than using, for example, bored piles. Tongue piles are reusable, can be dismantled and used at other sites, which makes them economically viable.

Dowels are made of high-strength metal and can be used many times

Scope of application

Tongue piles are the most effective, quickly erected and economical fencing, which is why this design is used everywhere. This can be a sheet piling fencing of the pit, which allows you to create waterproof and completely airtight walls. Can be used to strengthen access roads on suburban area, embankments, slopes. Widely used as strengthening and arrangement of embankments and coastlines.

Often fencing is used to equip hydraulic facilities. In certain cases it is used for quality protection communications. With its help you can equip landfill fencing, collectors Wastewater and so on.

At construction work ah, near water, there is often no alternative to sheet piles

On our website you can find contacts construction companies who offer the service. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.

Installation of sheet pile fencing

The fence consists of individual elements (sheet piles) that are assembled into one structure. There are grooves on the sides of all elements that allow them to be easily and quickly connected into one structure.

Piles can be made from various materials, which differ in durability and characteristics:

Plastic. They are made of composites and PVC, reusable, but in most cases they are installed as permanent elements of the fence of coastal objects. They are considered inexpensive, but are not very durable.

Reinforced concrete. Installed only once. They are distinguished by energy-consuming installation and unprofitable dismantling. Can be used as additional strengthening of the foundation.

Wooden. Inexpensive but impractical option. They rot over time due to moisture and are used only once. Cannot be used as a reinforcing foundation frame.

Sheet piling can be made from different materials, but not all of them may be beneficial to use

Metal. The most economical, durable, versatile and functional option. Manufactured from alloy or high carbon steels. Reusable, easy to install, lightweight, compact, have high static load ratings, and high strength.

In most cases, a profile tongue is used, but there is also a tubular one made of metal. He is thick wall pipes with a large cross-section, which are hollow inside. They have a high load-bearing capacity and are very stable. Used on unstable soils where there are heavy loads on the structure. Can be combined with profile tongue and groove for maximum reinforcement of areas.

Installation of sheet piling pipes

Fencing technology

The installation of sheet piling fencing of the pit is carried out using the same technology. The process of immersion and construction of the required wall is carried out in accordance with the calculations carried out, which are indicated in the corresponding project. The design itself specifies the method of fastening, the depth of the fence and the type of tongue and groove. Before design calculations, a hydraulic engineering assessment of the soil must be carried out.

Installation is carried out according to the following principle:

held marking and further installation of special guides;

delivered equipment, well drilling may be required;

elements sink into the ground, installed in place;

carried out fastening according to the prepared project.

Installation of sheet piling is often carried out using special equipment

Driving piles can be carried out using several methods. One option is pressing with special installations. In another case, vibratory hammers are used. A hydraulic hammer can also be used. The cheapest method of immersion is considered to be driving, but it has negative sides– ground movement, damage to nearby structures. Therefore, it is not suitable for use near industrial complexes or in cities. The most delicate method is pressing; it can be used in densely built areas. Vibration driving is suitable for soft soils, can be used almost anywhere, and is characterized by productivity.

Video description

This video shows how to install sheet piling pipes using the vibration immersion method:

To install piles, specialized equipment and machinery are used, which can be used even on small objects. Minimizing the load on the soil and simplifying the driving of piles occurs using auxiliary technologies, for example, leader drilling. You can also simplify work processes by washing using hydraulic equipment. In some cases, a combined dive is used. Often, when constructing pits, a backfill of boards is used, which later acts as formwork for concreting. For picking, use an edged board or steel sheet, when used on soils with big amount groundwater, additional care must be taken for drainage.

In some cases, it may be necessary to reinforce the finished wall. To do this, they can install diagonal struts that support the piles, and they themselves rest on the foundation slab or the bottom of the pit. In other cases, it is necessary to use spacers in the form of horizontal beams; they rest against the walls and prevent it from tipping over. Sometimes optimal solution is the use of a distribution belt - these are horizontal beams, attached to tongues around the entire perimeter, strengthen the wall and distribute the load.

If necessary, the sheet pile fencing is reinforced with additional beams and spacers

Installation technology

There are practically no differences between vibration and impact immersion technologies. The only difference is the functionality attachments. Slinging and sequencing are absolutely identical.

Installation of the fence occurs as follows: technologies:

material supplied to the object;

crane tongue and groove distributed around the perimeter construction site;

held contour marking, a pile driving machine is used;

produced slinging and moving the sheet pile to the installation site;

on tongue and groove headrest is mounted loader, the fence is placed in place of driving;

tongue and groove vertically levels out, guided immersion is carried out;

slinging is dismantled, the sheet pile is immersed to the depth specified in the project.

Each sheet pile is immersed in this way. The work continues until a closed fence around the perimeter of the pit is obtained.

When all the tongues are buried in the ground, you can start digging a pit without fear of its walls collapsing

Calculations and cost of fencing

Calculations are required to determine the configuration, size of the wall and additional reinforcement. This will achieve the necessary strength and stability of the entire structure. In the calculation process, indicators of the overturning effect, the forces of the retaining walls, the coefficient of performance of the structure in the soil and the reliability of the wall are taken into account. The latter may have different differences depending on the type of fence and soil characteristics.

When determining the strength, the resistance of a meter of wall to loads, the resistance of the strapping, the standard resistance and the coefficient of operation of the structure in the ground are taken into account. The last indicator is the tensile strength of the locks, which takes into account horizontal loads, radial force, operating conditions coefficient and the standard tensile strength of the locks (varies depending on the type of steel).

Video description

About the rules for installing a safe sheet pile pit:

The final cost of the pit depends on the row important factors. First of all, the type of material used is taken into account, for example, boards, pipes, metal piles, Larsen sheet piling. The cost is also affected by the type of equipment used (pile driver) that is used to drive the sheet piles. The main cost item is the volume of work performed. However, the overall cost can be increased as a result of the need to use retaining boards around the perimeter, which act as supports to strengthen the wall.

The elements of the metal tongue interlock with each other like puzzles

Briefly about the main thing

Sheet piling is a strong and durable solution for arranging construction pits and strengthening banks near water bodies. This strengthening of the walls of the pits allows them to withstand heavy loads, and the sheet piles themselves are not afraid of the influence of moisture, high or low temperatures. It is considered one of the most economical options, since some types of tongue and groove can be reusable. There are also dowels that are installed only once. Metal, wood, plastic or reinforced concrete are used to produce sheet piles. Depending on the material used, the characteristics of the fence itself change. Before use, calculations are carried out to help achieve the best result.

To strengthen the walls of the pit during construction work, various technologies are used, among which the most common is sheet piling made from pipes. The use of used materials makes the construction of a protective structure much cheaper than the use of special sheet pile profiles for this purpose.

Type of sheet piling using pipes

In construction, tongue and groove piles are usually called driven piles, which can be wooden, reinforced concrete or metal.

The essence of such strengthening is that first, sheet pilings (piles) are driven along the perimeter of the future pit to the required depth, and only after that the soil is excavated. Thanks to this, the collapse of the walls is prevented as it deepens, the pit itself is obtained with a strictly specified correct shape, and displacement of the structures of neighboring objects is avoided.

Properties of pipe sheet piling in comparison with other types of structures

Experts unanimously consider the only advantage of such strengthening to be its low cost. Unlike more expensive materials such as Larsen tongue and groove, the use of pipes has significant disadvantages:

• Their use does not allow obtaining a monolithic waterproof surface, therefore fencing is not used in the construction of hydraulic structures and in conditions of high groundwater horizons.
• Due to the thin section of the material walls and large area when entering the ground, when it is driven in, the edges are significantly deformed.
• Since the elements of the device do not have a locking clutch, it is difficult to ensure their smooth entry into the ground, therefore, with increasing depth, the elements of the fence will deviate significantly from the given plane.

As a rule, sheet piling fencing of a pit made of pipes, the technology of which involves their one-time, non-removable use, simultaneously serves as support posts for formwork formation for carrying out concrete works. In this case, the drill-injection method of driving piles is used, when their cavity is filled with a water-cement solution. When the pipe is pulled out, a large cavity is released, which will cause many years of subsidence of the home paths.

Methods for making sheet piling fencing of a pit

Vibration loading of sheet piles

The most common method of installing sheet piles is vibration immersion. First, a well is drilled and a pipe is immersed into it. To secure it more firmly, the well is first filled with sand-cement or clay mixture. The installation of sheet piling for a pit made of pipes, pursuing the goal of maximum savings, involves the use of the vibro-immersion method as the most economical of the existing methods. In this case, the pipe experiences minimal load during immersion, which prevents its deformation at the initial stage.

The pile can be driven by screwing. To do this, a tip is welded at one end of it, providing a spiral movement.

Important! Before driving piles, geodetic surveys are carried out to determine soil properties and groundwater levels.

When using pipes, driving can be used at the final stage of immersion to achieve the desired depth or if passage fails when vibration immersion is less than 1.5 cm/min.

The depth of driving the sheet piles must be above the groundwater level. When making deep pits, sheet piling is made in two tiers. In this case, the upper tier is driven several meters wider than the design dimensions, and when the recess reaches 2/3 of the length of the driven piles, the second tier is driven in to the required size.

In deep pits, fastening with ground anchors is used.

• Using struts. The parameters of the struts are calculated in each case separately.
• Anchoring with additional piles and rods. It is used in cases where fastening from the inside will interfere with the work. In order not to interfere with movement, the rods are recessed into the ground.
• Anchoring with drilling of additional piles obliquely into the wall.
• Cantilever mount. In this case, the pile is supported by deep penetration into the ground, when the depth of the pit does not exceed 2/3 of its length. The depth limits using this method of fastening, made using the bored method, is 10 m.
• Spacer fastening using spacer frames or telescopic tubular spacers.

Mounting options

As they deepen, the installed piles are laid wooden blocks, forming a solid wall, or fence.

Basic rules for performing sheet piling strengthening

To construct the fence, large diameter pipes are used, ranging from 219 mm to 630 mm. Before starting work, the axes of the pit are laid out by drawing out the design dimensions in situ. While driving the supports, you must constantly monitor their vertical position. When driving, it is recommended to use wooden headers. SNiP allows a maximum deviation of the top of the pile from the plane of the fence of 15 cm. Support pillars can be secured with a horizontal belt if the depth exceeds 4 m. Such belts are made from an I-beam. To ensure uniform loading, wedges are inserted between each pile and the belt. The struts and spacers are attached to the belt beams. At a depth of more than 10 m, two or more belts are made, and the top one should be at least 1 m from the top of the pit.

Important! If it is necessary to remove piles for their repeated use, it is important to follow a safe procedure for dismantling the struts and struts.

To prevent corrosion, metal piles are sometimes coated with special primers.

Upon completion of work on the implementation of the sheet piling, an act of laying out the axes of it and the pit, an as-built survey, and an act of acceptance of work are drawn up.

The calculation of sheet piling for a pipe pit is made using special programs, which, due to their high cost, can be afforded by large specialized organizations. One of the simplest, the SpIn program, calculates the ratio of the diameter of the pile, the depth of its driving and the parameters of struts and struts. Manual counting will take a long time and requires in-depth knowledge.

Screenshot of Spin

The technology for performing sheet piling strengthening of a pit requires the use of special equipment and knowledge of the rules for calculating the structure, which ensures its strength and safety. Therefore, it should be entrusted to specialists who have licenses to carry out such work and issue official documentation.

Price

The cost of services for the manufacture of sheet piling fencing for a pit from pipes is given in the table.

Firm "StroyAllianceGroup»

In conditions of weak soils prone to loss of stability when applying dynamic influences when driving piles, moving construction equipment, unloading building materials etc., both deformations of pit fencing and spacer structures, subsidence and uplift of soil into the underground structure, accompanied by soil subsidence and deformation of the foundation structures of buildings adjacent to the excavation pit being developed, can occur.

In this regard, taking into account the schemes presented in Fig. 3.3-3.12, we will consider the most common technical solutions for ensuring the stability of sheet piling.

Rice. 3.3.

a- console; b - with horizontal fastenings with steel beams; c - with anchor walls made of sheet piles; G- with horizontal anchor plates; 1 - sheet pile fencing; 2 3 4 - anchor wall made of sheet piles; 5 - steel anchor rods; 6 - anchor plates laid on the ground

A. Open pit

• 1. Cantilever fencing, including those with stiffening belts made of steel beams of various sections, is used for pits up to 4-5 m deep, limiting dynamic impacts when moving construction equipment and prohibiting the storage of materials near the fence (Fig. 3.3, A). At the same time, in soft soil conditions, it is necessary to ensure that the sheet pile is buried below the bottom of the pit to at least 2/3 of its depth. To ensure the joint work of the tongue and groove, a strapping beam made of rolled steel, mainly I-beams, paired channels, or a sheet pile, must be installed on the top of the fence (Fig. 3.3, 2).
• 2. Temporary spacer horizontal fastenings from metal cans of various sections (mainly pipes with a diameter of 450-720 mm, I-beams or tongue-and-groove joints connected by welding) with a pit width of up to 15-20 m (Fig. 3.3, b). For large pits, intermediate rack piles made of sheet piles or column I-beams are used, as well as structural elements walls of the building, carried out before the development of the soil during the stage-by-stage excavation of the pit along the grips (Fig. 3.4, 3). Spacers are arranged in one or several tiers with a step determined by calculation, which is usually 4-6 m.

Rice. 3.4.

I - sheet piling; 2 - distribution belt (banding beam); 3 - horizontal steel beams; 4 - intermediate supports (piles-racks) made of sheet piles

Rice. 3.5.

a, c- strapping beams made of I-beams; b- assembly for fastening the anchor rod to the strapping beam made of channels; V- strapping beams made of two I-beams; d,f- strapping beams made of two and one sheet piling, respectively; / - tongue and groove; 2 - I-beam; 3 - steel pin; 4 - steel pipe or wooden beam; 5 - channel; b - steel supporting gusset; 7 - anchor rod; 8 - thrust steel plate; 9 - steel washer; 10 - screw; 11 - fixing steel wedge

Design solutions for fastening sheet piling fences for pits up to 10-15 m wide are presented in Fig. 3.5, A, for pits up to 20-30 m wide in Fig. 3.6.

3. To reduce metal consumption, inventory steel frame elements with replaceable end parts can be used as spacer systems for fastening sheet piles

Rice. 3.6.

(Fig. 3.7, A). Jacks are included in the outer rods adjacent to the sheet pile, allowing you to monitor the movements of the pit fencing and control the forces in the spacers.

Rice. 3.7.

A- steel inventory frames with jacks; b- reinforced concrete trusses; I- tongue and groove; 2 - strapping beams; 3 - steel inventory frame elements;

4 - jacks; 5 - reinforced concrete trusses (intermediate supports are not shown)

Frame structures in some cases are made of horizontal reinforced concrete trusses with intermediate posts

• (see Fig. 3.7). After developing the pit, such structures can be included in the ribbed floors of the underground floors of the structure. On trusses that cover the pits of large spans, it is possible to place construction and technological equipment, as well as store materials during the construction of the underground part of the building.
• 4. Fastening the fence to vertical anchor walls or horizontal slabs with steel rods at a distance of at least S = N k tg(45° - Нк - pit depth, c, d). Such a constructive solution for fencing requires additional space beyond the boundaries of the pit. It does not provide horizontal stability below the bottom of the pit. The attachment point for the anchor rod to the fence is shown in Fig. 3.5, b. Anchor walls can also be constructed from groups of sheet piles (2-3 gypsum), immersed every 2-5 m along the contour of the fence. Anchor rods are made from reinforcing bars, which allows you to adjust their tension depending on the horizontal movements of the sheet piling. When the pit depth is over 6 m, anchor rods are installed in trenches laid 2-3 m below the ground level.
• 5. “Island” method with soil berms and braced fastenings made of steel beams or trusses resting on sections foundation slab or in temporary column piles made of sheet piles or I-beams, immersed in the bottom of the pit (Fig. 3.8, a-e). The pit is developed in stages: first, the soil is dug out to its full depth, with the exception of zones (soil prisms or berms) adjacent to the sheet piling, then corner horizontal struts from pipes are installed, sections of foundation slabs are made in the pit, into which the braced fasteners rest, on the second stage, the final completion of the pit is carried out and the underground structures of the building are erected. With the necessary design justification, the fastening of sheet piling can be done by supporting horizontal struts in the structure of the building under construction (floors or walls) (Fig. 3.8, V). Spacer structures are sequentially dismantled as the building structures are erected and the pit is backfilled.
• 6. Fastening sheet piling fences with soil injection anchors, buried in dense soils beyond the zones of active soil pressure on the fences and taking up pulling forces (Fig. 3.8, G). The amount of effort perceived individually

The standard anchor for clay soils is in the range from 0.1 to 0.5 mN. Anchors are placed along the perimeter of the pit in increments of 0.8-3.0 m with a horizontal inclination angle of up to 30-60°. Anchor rods are made from drill pipes, reinforcing bars, ropes or pipes, which are used when drilling and flushing a well with cement, clay or polymer solution. For fastening with a sheet piling wall, holes are made in it, and anchor rods are attached to a steel strapping beam made of a channel or I-beam. In conditions of weak soils, this solution has limited use, since it requires deepening to significant depths (over 25-30 m), and when installing anchors under existing engineering communications, roads or buildings, additional deformations may occur in the structures of the latter due to changes in the stress-strain state of the soil due to its interaction with the embedding of the anchor. This design solution, despite the increased requirements for the quality of work and qualifications of the contractor, high cost and labor costs, is effective for large-volume pits when it is not possible to use spacer structures installed inside the pit.

7. Strengthening the soil along the entire depth of the sheet pile, as well as creating soil-cement diaphragms over the entire area below the foundation pit using jet cementation technology (Fig. 3.8, d). To create continuous diaphragms up to 1500 mm thick, soil-cement piles are arranged on a grid of 600x520 mm, the design strength of the soil-cement material is assumed to be about 1.0 MPa, and the deformation modulus is 400 MPa. The consumption of materials per 1 m of drilling is: water 200-350 l, cement 300-650 kg; complex additives 7-12 kg.

Rice. 3.8.

a B C- with ground berms and struts into the foundation slab; G- with ground anchors; d- with soil-cement diaphragms made using jet technology; 1 - sheet pile fencing; 2 - distribution belt (banding beam); 3 - temporary, soil berm; 4 - steel strut or truss; 5 - foundation slab or piles; 6 - temporary anchor wall (solid or intermittent); 7 - load-bearing structures of the underground floor; 8 - horizontal steel beams; 9 - ground anchor;

10,11 -vertical and horizontal soil-cement massif

B. A closed pit in which sheet piling is a permanent structure that takes the loads fromdesigns building

I. Fastening the fence using horizontal floor discs, concreted using the “top-down” technology (top-down). With this technology, sheet piling can be combined with trench concrete walls in the ground. The development of the soil is carried out through technological openings in stage-by-stage floors, concreted directly onto the formwork laid on the ground. For floor supports, permanent piles are used - columns, installed before the main contour of the pit fencing is completed.

To increase productivity when extracting soil and concreting floors, the so-called “semi-closed” method is used (semi top-down), when, along the contour of the sheet piling, cantilever sections of floors 3-6 m wide and large openings in the center are arranged, which are concreted after complete removal of the soil and installation of waterproofing of the lower level (Fig. 3.9, A). Overlappings along the perimeter of the pit are carried out using the “top to bottom” method, and in the central part, after removing the soil, classic scheme- "down up". The pit fencing is secured due to the spatial work of the perimeter sections of floors.

With this scheme, two options for performing work are possible.

Option 1. The installation of sections of floor discs along the perimeter is carried out in the process of stage-by-stage excavation of soil from the pit in the following sequence (Fig. 3.10):

• immersion of the sheet pile along the perimeter of the structure (Fig. 3.10, A);
• immersion of column piles (Fig. 3.10, b);
• concreting the floor slab of the first underground floor on the ground;
• within the contour of the slab, technological openings are arranged through which the soil will be extracted and descended necessary equipment and workers (Fig. 3.10, V);
• extraction of soil within the first underground floor to the surface and installation of an underlying monolithic floor with technological holes (Fig. 3.10, G);
• the specified operations of sequential soil extraction and installation monolithic floors repeat until the level is reached

Rice. 3.9. Methods for constructing underground structures using top-down technology: a- semi-closed method; b- with inventory steel trusses; 1 - tongue and groove; 2 - monolithic ceiling; 3 - intermediate piles-columns; 4 - technological hole for soil extraction; 5 - inventory farms

construction of the last underground floor by installing a monolithic slab on the ground with horizontal waterproofing(Fig. 3.10, d). On last stage From the last underground level, excavation equipment and formwork are removed through technological holes, which are then concreted.

Option 2. Preservation of soil berms that prevent the movement of sheet piling until the installation of floors. The work is carried out in the following sequence (Fig. 3.11):

• the sheet pile is immersed around the perimeter of the structure (Fig. 3.11, o);
• from the level of the ground surface, outermost piles-columns are made (Fig. 3.11,5) to further support the floors along the perimeter of the sheet piling fence (Fig. 3.11, b);
• develop a pit to the design level while maintaining soil berms along the perimeter of the fence (Fig. 3.11, 7). From the level of the bottom of the pit, piles are made (Fig. 3.11,9), on which waterproofing and the foundation slab of the central part of the building are installed (Fig. 3.10, V);
• erect the frame structures of the central part of the building. In parallel, at the level of the ground surface, sections of floors along the perimeter of the sheet piling are concreted. To extract the soil, technological holes are left (Fig. 3.11, 7);
• in areas adjacent to the sheet pile, soil is removed through technological holes within the first underground floor. They arrange a monolithic ceiling, which I also connect! with the frame structure of the central part of the building (Fig. 3.11.6);

The specified operations of sequential soil extraction and installation of sections of monolithic floors are repeated until the level of the last underground floor is reached, with the installation of a monolithic slab. At the last stage, excavation equipment and formwork are removed from the last underground level through technological holes, which are then concreted (Fig. 3.11, e).

Rice. 3.10. Stages of technology for constructing underground structures using the “top-down” technology with load-bearing enclosing structures made of sheet piles: a d- stages of installation of underground structures; 1 tongue; 2 - jib crane; 3 - vibrating loader; 4 - intermediate piles-columns; 3 - drilling rig; b- grab; 7-technological hole for soil extraction; 8 - monolithic ceiling; 9 - excavator; 10 - support tables; 11 -concrete mixer truck; 12 - concrete pump; 13 - above-ground load-bearing structures; 14 - monolithic slab with horizontal waterproofing, foundations laid on the ground 69

Rice. 3.11.

/ - tongue and groove; 2 - jib crane; 3 - vibrator; 4 - drilling rig; 5 - column piles along the perimeter of the fence; 6 - grab; 7 - soil berms; 8 - foundation slab of the central part of the building; 9 - bored piles installed from the bottom of the pit; 10 - monolithic floors along the perimeter of the sheet piling; // - technological hole for soil extraction; 12 - monolithic ceilings of the central part of the building;

13,14 - concrete pump and fuel mixer truck, respectively; 15 - excavator

There are solutions developed by MIIOSP named after. Gersevanov, in which inventory metal truss structures are installed in the upper tier of the pit (see Fig. 3.9, 5). The trusses are supported by sheet piling, and the underground floors, concreted in stages as the soil is excavated, are suspended from the truss structures. After concreting the building frame elements, temporary suspension structures and trusses are dismantled.

The method makes it possible to minimize the influence of construction processes and underground soil development on the stress-strain state of the pound massif and structures located nearby buildings and structures. At the same time, this technology is the most expensive and requires high qualifications from a specialized construction organization.

The composition of machines that makes it possible to implement these technologies in a complex mechanized way is presented in Table. 3.4.

Table 3.4

List of machines and equipment used in the technology of constructing underground structures using the “top-down” technology with load-bearing enclosing structures made of sheet piles

Technological stage	Equipment used
Sheet piling	Vibrating loader on a crane, drilling rig or excavator
Device intermediate pile-columns	Drilling rig, pneumatic wheel crane, concrete pump, fuel truck
Device monolithic floors	Pneumatic wheel crane, welding unit, concrete pump, concrete truck
Removing soil from under floors	Mini-excavator on pneumatic wheels, grab on a crane. It is possible to extract soil to the surface through technological holes along belt conveyors installed on the floors of underground floors

Possible Constructive decisions The fastenings of monolithic floors to sheet piling fencing are shown in Fig. 3.12.

Based on the presented technological schemes, taking into account the analysis of experience in working in difficult soil conditions on the installation of sheet pile fencing and their fastenings, the authors performed a technological calculation of several options for fastening the fencing of a conditional PIT with a depth of 6 m with plan dimensions of 40x30 m. The length of the sheet pile is 18 m. The following technological technologies were considered options:

• option 1 - installation of temporary horizontal spacer beams made of steel pipes with a diameter of 630 mm, mounted in increments of 6 m, with intermediate support on sheet piles; For all options, a strapping belt made of a steel I-beam with a height of 400 mm is installed around the perimeter of the fence;
• option II - “island” method with soil berms and braced fastenings made of steel pipes 12 m long with a diameter of 426 mm, installed in increments of 6 m and secured to sections of the foundation slab in the pit;
• option III - fastening sheet piling fences with ground injection anchors from rods with a diameter of 73 mm and a length of 30 m, performed in one row with a step of 2 m; anchors are provided using Titan technology (Ishebeck GMBH) ;
• option IV - fastening the fence with steel rods to a discontinuous anchor wall made of sheet piles (three sheet piles of the 4Z-36-700 Arcelor brand per pile) 9.5 m long. Rods with a diameter of 75 mm, a length of 15 m are laid in increments of 5 m in trenches with a depth of 2 .0 m;

Rice. 3.12.

a- on steel support tables; b, V- on monolithic reinforced concrete belts; 1 - tongue and groove; 2 - beam or floor slab, 3 - horizontal steel beam, 4 - support table welded to the tongue, 5-monolithic

reinforced concrete belt

option V - cementation of the soil along the entire depth of the sheet piling, as well as the creation of soil-cement diaphragms 2 m thick under the bottom of the pit with a pitch of 600x520 mm (close to the sheet piling with a pitch of 500x440 mm).

Cost indicators were adopted based on territorial current unit prices and data from suppliers of building materials. The timing of the work was calculated according to ENiR standards, taking into account the productivity of modern equipment. Manufacturability criteria were calculated using formulas (2.1)-(2.3).

Differential (simple) criteria for the manufacturability of the device for fastening sheet piles are presented in Table. 3.5.

Table 3.5

Simple criteria for the manufacturability of the installation of sheet piling reinforcements

Options		Simple criteria for manufacturability X.
		Cost, thousand rubles	Metal consumption, t	Cost of materials, thousand rubles	Labor costs	Area increase factor	Duration, days
	With horizontal struts
	With soil berms
	Unpaved anchors
	With anchor wall
	Jet cementation

Note: highlighted in the table best values according to the considered indicator of manufacturability; the area increase coefficient was calculated as the ratio of the area occupied by the fencing structures to the area of ​​the pit; When calculating the productivity for option 3, the work on developing the pit and installing sections of the foundation slab was taken into account.

Results of bringing simple criteria X in dimensionless quantities are given in table. 3.6

Table 3.6

Simple criteria in dimensionless form

Options		Simple criteria in dimensionless form: T" = x„ /xG % , T" = xG/x «
		Price	Metal intensity	Cost of materials	Labor costs	Increase	Duration
	With horizontal struts
	With soil berms
	Ground anchors
	With anchor wall
	Jet cementation

To calculate the generalized and integral criteria for manufacturability, the weight coefficients /-x, /^ were determined depending on the significance of each criterion according to the method of V. G. Gmoshinsky, adopted in engineering forecasting.

For example, for a test pit during the construction of the second stage of the Mariinsky Theater with the loosening of sheet piling steel pipe the value/^ was 1.3%, which required additional reinforcement of the sheet piling in the form of soil consolidation using jet grouting methods.

It should be noted that when installing sheet piling fencing for pits located near historical buildings in soft soils, values ​​of equivalent rigidity should be taken^

Taking into account the above in table. 3.10 presents modern experience in constructing sheet piling fencing for pits over 6 m deep in St. Petersburg, showing that the use of special, mainly vibration, technologies for driving sheet piles in combination with additional measures for the installation of various retention systems ensures the proper quality and stability of pit fencing.

The choice of technological parameters for the installation of sheet piling fencing and systems for ensuring their stability in conditions of weak dynamically unstable soils is an important technical task that requires, first of all, competent calculation justification based on modern techniques and software systems. The basic principles and methods for calculating sheet piling are discussed in the next section.

Examples of installation of sheet piling fencing for pits in St. Petersburg

Table 3.10

		Technology dives
TRC Gallery, Litovsky Ave.		Vibrating		Ground anchors and ground berms and struts supported on a foundation slab
Shopping center Stockman, Nevsky pr.				Ground-cement diaphragm at a depth of 17-20 m. Wall in the ground, floors arranged using top-down technology
Administrative building of the bank, Malookhtinsky Ave.
Second stage of the Mariinsky Theatre, Kryukov Canal				Overlapping using top-down technology, jet technology
Hotel complex Park Inn, Goncharnaya st.				Wall in the ground. Horizontal spacer beams
Office center, Pochtamtskaya st.				Soil-cement i diaphragm at a depth of 7-10 m. Horizontal spacer beams
Reconstruction of the building into a hotel complex, emb. R. Moiki, 73, 75, 77, 79		Indentation		Overlapping using top-down technology
Residential building, Deputatskaya st., 34A		Vibrating		Ground berms and horizontal bracing beams

End of table. 3.10

		Technology dives		Sheet piling fastening technology
Office center, Nevskaya Town Hall, Degtyarny ner.		Vibrating		Ground anchors 30 m long
Residential complex, Medikov Ave., 10				Horizontal spacer beams
Residential building, Rybatsky Ave.,			12-20	Ground berms and struts supported on a foundation slab
Residential building, st. Pobeda near the house 18 GG on Moskovsky Ave.		Indentation Vibrating		Horizontal spacer beams in two tiers on intermediate columns
Residential building, st. Smolny, 4, bldg. B-2, B-5, B-6		Vibrating		Horizontal spacer beams on intermediate columns
Automobile plant "Magna" in the village. Shushary, Moskovskoe highway.				Horizontal spacer beams

Note: //.. L- pit depth and sheet pile length, respectively.

Sheet piling barriers were developed to strengthen the walls of excavations during construction work. Such fencing reliably protects workers and equipment from ground collapses.

On the territory of the Russian Federation, the method of static indentation of sheet piles began to be used only in the late 90s of the 20th century. When constructing protective structures from sheet pile profiles in America and Europe, most are built using this method.

Initially, the tongues were made of wood. A distinctive feature of a tongue and groove board was the presence of a tongue and groove on the sides of the board. They were intended to reliably connect individual boards into a single shield.

With the development of construction skills and the growth in the scale of construction, reinforced concrete ones replaced wooden tongues. Such a structure can serve not only as a temporary fence, but also in the future carry a supporting load during the construction of the building.

The disadvantage of this type of tongue and groove is their low resistance to difficult soils which is why they often go sideways when they hit a solid obstacle. Cracks also often appear, since reinforced concrete is very sensitive to bending.

The most economical option is to press metal sheet piles.

After work in the pit is completed and the piles are no longer needed, Larsen metal sheet piles can be pulled out and used in the construction of other objects. This greatly reduces the cost of the method.

Methods for driving sheet piles into the ground

Main in modern construction There are 3 ways to immerse the sheet pile:

1. Immersion driving;
2. Static indentation.

Immersion driving

This method was used to drive the first piles in construction. The main advantage is its technological simplicity and availability of all necessary equipment.

The disadvantages include the need for powerful and energy-consuming installations. Also, when such equipment operates, it produces a lot of noise and a high impact on the ground.

Helpful advice

All vibration loads have Negative influence on the condition of neighboring buildings, creating cracks in the foundation and walls.

If the tongue and groove hits some obstacle during impact driving, it may become deformed, and along with it the tongue-and-groove fastening lock.

Vibration loading of sheet piles

Vibration immersion of the sheet pile is more than economical option in terms of energy consumption. Also, the level of noise and vibration generated is noticeably lower than that of impact technology. Which has a positive effect on the possibility of carrying out work near residential buildings and protected cultural sites.

But the mechanism of immersion under the influence of vibration makes it impossible to use such equipment near subway tunnels or large pipelines and other highways.

Static indentation of tongue and groove

The most modern technology This is the static indentation of the Larsen tongue.

An excellent option if you need to carry out work in densely populated areas of large cities or near architectural monuments.

This method will be especially relevant in areas with dilapidated buildings, landslide zones, where any impact can lead to an emergency.

Sheet piling fencing for a pit in Sheremetevo, made by specialists from ArktikGidroStroy

Sheet piling in Moscow, made by specialists from ArktikGidroStroy

Sheet piling fencing of a pit made from Larsen sheet piles with spacers, made by specialists from ArktikGidroStroy

Indentation of the sheet pile performed by specialists from ArktikGidroStroy

Vibration driving of pipes and sheet piles during the construction of a temporary bridge, performed by specialists from ArktikGidroStroy

Advantages of the static indentation method

The main advantages of using the indentation method when driving sheet piles are:

• Suitable for working near residential buildings and cultural objects;
• The ability to carry out work near large pipelines and metro lines due to the complete absence of vibration and shock loads on the ground;
• High speed of construction of the barrier and savings in the construction budget;
• The settlement of the entire barrier is uniform, as is the process of immersion in the ground;
• The use of modern special equipment allows you to monitor the dive online and make the necessary adjustments;
• This technology is environmentally friendly;
• The final load-bearing capacity of all piles that were installed using the static indentation method is higher on average by 10% than that of piles installed using the classical impact method.

Technology for installing sheet piles using the indentation method

With the static method of pressing a sheet pile, it is installed at the planned immersion location, after which it is pressed into the ground using a hydraulic drive. Modern technology allows you to apply pressure from a ton to several tens of tons.

Due to small area in cross-section, a sheet pile cuts into the ground much more easily than a classic reinforced concrete one.

Helpful advice

Immersion of the sheet pile using the indentation method allows you to avoid restrictions when working near residential buildings due to the complete absence of vibration and noise. This is especially important when carrying out work within large cities.

Watch the video to see how sheet piles are installed in our company:

Machinery and equipment used

The main force used during the indentation pile driving procedure is a constant static load. For such purposes, extremely powerful construction equipment is used.

All pile driving machines are designed on the principle of lateral wedge gripping of the sheet pile and immersing it in the well, which is prepared in advance.

Modern electronics help to adjust the angle of insertion of the sheet pile in a timely manner and ultimately obtain a perfectly even row of piles. It is also possible to create sheet piling barriers in round and angular configurations.

Several types of equipment are most widespread in the market for tongue pressing services:

• Hydraulic pile driving unit (HPU) TITAN DTZ Mainly used to create pile foundation under the building. The maximum force is 320 tf;

• When working in dense urban areas or the need to organize a large pile area, use the SUNWARD ZY J120 installation, which is completely silent, environmentally friendly and suitable for all types of piles;

• SVU-V-6 is a completely independent and standalone installation, capable of performing the entire range of work with sheet piles and moving to to the right place installations.

Types of Sheet Piling

The following types of sheet piling are currently available on the market:

• Larsen tongue and groove is the most popular type of tongue and groove at the moment. Technologically, it is a metal profile various forms, made of high quality metal. Larsen tongue and groove sheets come in a trough shape or a Z-shape. Side walls have special curves that act as locks for connecting individual tongues into one-piece design. As a result, such tongues form a strong and monolithic wall, which reliably protects against collapses and other incidents;

• Standard metal tongue - used in cases where static pressing of a Larsen tongue is too expensive. After installation, the iron tongues are removed from the ground and can be reused if they were not damaged during installation.

• Concrete sheet piles are more expensive than iron ones, but after construction they continue to perform a supporting function. They are most often used in the construction of multi-storey buildings.
• Wooden ones are practically no longer used, as they are not able to withstand high loads and cannot be reused.

Our advantages in the installation of sheet piling

Our specialists are always ready to advise you free of charge on any issue of sheet piling, as well as to guide you through the range of sheet piles.

We provide a service for the supply of used sheet piles and the removal of already used Larsen sheet piles.

We have accumulated extensive experience in implementing a wide variety of projects of any complexity. The start time for work from the date of application is 48 hours.

A key feature of cooperation with our company is that we sell Larsen sheet piles with the possibility of buy-back. This procedure will help you return up to 80% of the original cost.

This is one of the types of rolled metal, developed in its form at the beginning of the 20th century. The product has a wide range of applications from construction to hydraulic engineering. The special profile shape makes the tongue and groove the best solution for many construction tasks.

Larsen tongue and groove device

A sheet pile is a hot-rolled product made from steel with a high carbon content. Profile form in cross section resembles a trough with edges equipped with locks - they allow you to fasten products to each other when installing vertical enclosing structures, for example, supporting walls.

Control of the production of Larsen sheet piles is regulated by GOST 4781-85 “Hot-rolled steel profiles for sheet piles. Technical conditions". There is no separate standard for the product, so manufacturers rely on the developed specifications.

The document presents standard sizes sheet pile beam, grade of steel used for production, procedure for quality control and acceptance of products and other important parameters.

Varieties

The product is used in different areas of construction, so the technical characteristics, appearance of the profile and the grade of steel used differ among different types.

Larsen sheet pile L4

The profile is made of steel 16KhG (ST3KP). Its characteristics:

• useful width of the product in the center of the lock - 405 mm,
• wall strength is 517-518 kN/m;
• thickness of inclined edges - 9.5 mm;
• permissible resistance 1 l.m. supporting wall - 2200 cm³/m;
• weight of Larsen sheet pile L4 - 74 kg/m;
• weight of 1 m² of structure - 182.7 kg.

Larsen sheet pile L4 is produced at 2 factories:

1. Russian Mining and Metallurgical Company;
2. "DMK" (Ukraine).

The product is widely distributed in Russia and the CIS countries; it can be purchased from various suppliers in the primary and secondary markets.

Larsen sheet pile L5

For the production of this rolled product, ST3KP steel is used. This is a more powerful profile than L4:

• useful profile width between locks - 420 mm;
• wall strength - 696…800 kN/m;
• permissible resistance 1 l.m. supporting wall - 2962 cm³/m;
• weight of Larsen sheet pile L5 - 100 kg/m;
• weight of 1 m² of structure - 238 kg.

Like L4, L5 sheet pile is produced by the Ukrainian “DMK” and the Russian Mining and Metallurgical Company. You can buy the product throughout Russia at reasonable prices from various suppliers and intermediaries. On sale you can find rolled VL607 - this is an analogue of the L5 sheet pile from the Czech company Evraz.

Larsen sheet pile L5-UM

This representative of this type of rolled steel differs from its predecessor in the quality of the steel used for production - it is resistant to corrosion and contains copper.

• Useful profile width between locks is 543 mm;
• wall strength - 906 kN/m;
• thickness of the inclined edge - 11 mm;
• permissible resistance 1 l.m. supporting wall - 3555 cm³/m;
• weight of Larsen L5-UM sheet pile is 114 kg/m.

Other types

Larsen tongue and groove piles differ not only technical characteristics, but also the shape of the castle:

• S-profile;
• L-profile;
• Z-profile.

In all cases, the lock forms a tight connection between adjacent profiles.

Beams made of non-metallic materials are used for various purposes:

• plastic;
• reinforced concrete;
• tree.

However, steel tongues are used most often and are in demand.

Application area

Larsen sheet piles are used in civil engineering and in the construction of hydraulic structures for various purposes:

• temporary strengthening of foundation pits installation work;
• protection of pits from filling with groundwater - the sheet pile connection is completely sealed and retains its properties for several decades;
• strengthening the walls of tunnels, highways and local roads;
• fixing coastlines and protecting them from erosion;
• arrangement of dams, dams, locks, berths, etc. and their repair;
• construction treatment facilities;
• strengthening soils prone to sliding.

The tongues, connected by locks, form a sealed and durable wall that can take significant loads. The products are immersed in the ground, leaving a fence of the required height above ground level. The installation of sheet piling walls is much more profitable than the installation of concrete and reinforced concrete structures, therefore metal profiles are most often preferred in cases where it is necessary to contain the pressure of water and soil.

Installation

The method of driving the Larsen sheet pile depends on the length of the product and the characteristics of the soil. There are 3 methods for installing profile piles:

• clogging;
• vibration immersion;
• indentation

The tongue is inserted into the ground according to the design position, the next one is buried inverted 180° relative to the previous one in order to be able to close the mounting lock, and so on.

Clogging

This method is used outside urban areas, since vibration transmitted to the ground has a destructive effect on the foundations of nearby buildings and structures.

Hammering is carried out using a special technique - copra. This machine is equipped with an impact mechanism, the force of which on the driven pile is adjusted depending on a number of factors (parameters of the sheet pile, soil).

Larsen tongue driving is the fastest and cheapest method of driving steel support walls.

Vibration immersion

The second most popular method is vibration immersion. This method is used in cases where it is not possible or necessary to hammer in elements of the supporting wall (in reservoirs, on coastlines, on soft soils saturated with water).

Vibration is provided by a mechanism that produces low frequency vibrations. It is mounted on excavators, cranes and other equipment.

How the dive occurs:

• the tongue is secured in a vibration mechanism using slings;
• align the stand to the design position;
• the installation presses on the pile, emitting vibration, which helps the steel product sink into the ground.

The method does not have a significant effect on the soil; however, its use within dense buildings is limited. In addition, the method has a significant drawback - high cost compared to driving.

Indentation

The most expensive and only method of driving sheet piles permitted for use in urban development is indentation. The process is carried out by a special pile-pressing unit (PVU) on caterpillar tracks. The tongue is attached to the movable mechanism in a vertical position, and the profile is immersed in the ground to a specified depth.

Dismantling

When the supporting wall becomes unusable or the need for it disappears, it is dismantled. The Larsen sheet pile is removed using a vibrating machine. Using only a crane is ineffective - the friction forces in the ground are significant, and only short-amplitude vibrations can weaken them.

The tongue and groove are fixed in a vibration installation suspended from a crane, the vibration generator is turned on, and the pulling force is gradually increased.

As a rule, the cost of even used sheet piles exceeds the cost of dismantling them, so the work pays off well. For this reason, organizations that extract sheet piles themselves pay their clients the difference in prices; the latter automatically resolve the issue of selling unnecessary profiles.