Larson steel sheet piles are a type of building material featuring interlocking devices at both ends, allowing them to be connected with other panels. The formed steel sheet wall can serve as a secure support, water and sand barrier in water or underground. Due to its unique structure, it boasts distinctive advantages: high strength, lightweight, excellent waterproofing properties; durability with a lifespan of 20-50 years; and reusability, typically for 3-5 cycles. Their environmental benefits are significant, as they can greatly reduce the amount of soil excavation and concrete used during construction, effectively protecting land resources. In fact, Larson steel sheet piles also have strong emergency rescue capabilities, particularly in flood prevention, landslides, collapses, and shifting sands, where they show rapid results. Of course, the simplicity of their construction, shortened project timelines, lower construction costs, and independence from weather conditions are major advantages of the steel sheet piles. During use, they can simplify the complex procedures for inspecting materials or system performance; ensuring good adaptability and interchangeability. Next, the editor of Xianji.com will introduce you to the relevant knowledge of Larson steel sheet piles, including: construction techniques, precautions, potential issues encountered during construction, and their solutions. Take a look!
Larson steel sheet pile construction technique
Construction process: surveying and marking → installation of construction piles → assembly of frames → driving steel sheet piles → excavation of foundation pit to subgrade level → setting of drainage system → backfilling → removal of steel sheet piles.
One, measurement and stakeout
Prior to excavation, the centerline of the sewage pipeline and the excavation boundary lines are marked according to the coordinates and dimensions shown in the drawings. Temporary benchmarking points are also set up as the basis for elevation control during the pipeline construction. The centerline should be extended to both wooden stakes for easy centerline checks at any time. The measurement and marking results must be reviewed and confirmed by the supervising engineer before proceeding to the next stage of construction.
Construction Pile
Measure the orientation and lay out the position for the insertion of Larsen steel sheet piles. Use a crawler-mounted hydraulic single-drum vibrating pile hammer (with a clamp), first drive piles, and install a Larsen pile every approximately 9 meters. Place a horizontal guide clamp between the two middle piles, lower the vibration box to the storage area of the steel sheet piles using a crane, fit the steel sheet pile into the clamp and secure it, then hoist it to the pile insertion position, vertically insert it into the pile slot, check for accuracy, and then start the vibration hammer to sink the pile.
Installation Rack
A steel sheet pile is placed horizontally between two piles to create a guide clamp. During pile driving, the vibration box is moved to the storage area of the steel sheet piles, where it is inserted into the pile clamp and secured. Then, it is hoisted to the pile driving position, vertically inserted into the pile hole, and checked for accuracy before starting the vibration hammer to drive the pile.
4. Drive and hammer in steel sheet piling
1. During pile driving, the crane delivers the vibration box to the steel sheet pile storage area, fits the steel sheet pile into the clamp and secures it, then hoists it to the pile driving location, vertically inserts it into the pile hole, checks for accuracy, and then activates the vibration hammer to drive the pile.
2. When vibrating the pile into the soil layer, if encountering underground debris and small stones or sand, you can vibrate and pull out the sheet pile, then reinsert it. Repeat this up and down vibration insertion multiple times until it is fully inserted. During the pile driving process, the descent speed of the hook should be controlled to maintain the suspended state of the pile sinking, ensuring its verticality.
3. Field staff must follow instructions. When lifting 9m steel sheet piles, the hoisting rope must be securely attached to the 1.8m to 1m sturdy section of the pile to prevent failure and slippage. The operator of the control box should closely monitor the crane's rotation direction, tighten each pile securely, and frequently inspect the rope to prevent damage and potential accidents.
4. After driving the Larsen steel sheet piles and anchor piles, weld steel haunches above the Larsen piles, and place and secure steel sheeting, then weld cross bracing for support reinforcement.
Excavation of foundation pit
1. Primary Equipment:
A. Excavation equipment includes excavators, dump trucks, and more.
B. General equipment includes: shovels (both pointed and flat heads), hand carts, thin white wire or 20-gauge wire, and steel measuring tapes, etc.
2. Construction Method:
A. Prior to earthwork excavation, remove and dispose of all underground and overhead obstructions within the construction area, in accordance with the requirements of the construction plan.
B. The location control lines (posts) of the building or site, standard level posts, and the dimensions of the open trench white lines must pass inspection and be deemed qualified; pre-inspection procedures must be completed.
C. When working at night, adequate lighting facilities must be provided; clear signs should be set up at hazardous areas, and the excavation sequence should be arranged reasonably to prevent incorrect or excessive excavation. The soil excavated should be transported to the dump site using dump trucks.
D. Roads and unloading facilities that construction machinery will pass through on-site should be inspected in advance, and reinforced or widened as necessary for preparatory work.
E. In areas where mechanical construction cannot be performed, such as grading the slope, clearing the bottom of the pit, etc., all work should be carried out in conjunction with manual labor.
F. Based on the site conditions, we plan to use the Kobe 260 excavator for excavation. Due to the excavation width of 3~3.5m, only a single-pass excavation method can be employed. Layered excavation is not feasible as the excavator cannot rotate at the layer position to remove soil. Continuously measure the foundation pit's edge line and base elevation to ensure the soil is in place without over-excavation, and reserve a 10cm buffer for manual cleanup.
G. Prevent excavator impact on piles and disturbance of the foundation bearing layer.
H. Install temporary drainage ditches and a sedimentation pond inside and outside the foundation pit (1m from the edge of the pit), and assign a dedicated person to handle drainage.
Section 6: Drainage System Arrangement
Based on geological survey data, the groundwater level at this site is high, and groundwater is visible during the local excavation work. Therefore, corresponding drainage and water lowering measures must be taken before and during the foundation pit excavation to ensure the safety of the foundation pit construction. Temporary ditches, water lowering wells, and collection pits should be set up around the foundation pit to timely drain the water out.
2. Four 100mm pumps are used for water extraction within the foundation pit, with an additional 15 50mm pumps for groundwater extraction and 5 spare 50mm pumps on standby.
Section 7: Refilling
Upon completion of the wastewater pipeline construction and reaching the backfill condition, clean the foundation pit debris. Use medium to coarse sand that meets the design requirements for layered compaction and water-tight backfill, starting from one end and moving towards the other, layer by layer from bottom to top. During backfilling, attention should be given to protect the structure from damage.
8. Extract steel sheet piles
1. Excavation backfill must be completed before removing steel sheet piles; piling removal is conducted using a 20-ton crawler crane for lifting.
2. Prior filling of gaps between steel sheet piles is mandatory before removal.
3. When removing each steel sheet pile, ensure the retrieval rope is properly tensioned, keeping the hook perpendicular to the horizontal. Slowly pull the pile out. Equip winches in narrow road areas, drag them out after removal. Load a truck, return an empty one, and maintain a clean construction site.
4. During the pile extraction process, assign personnel for monitoring. If the monitor issues a warning, the extraction speed must be slowed or the pile extraction must be halted until appropriate measures are taken before resuming.
Section 9: Simplified Calculation of Steel Sheet Piling Load
1. Based on the soil layer descriptions provided in the geological data from the design drawings, the soil layer parameters in this calculation are taken as follows based on experience:
A. Steel sheet pile top elevation: H1=18.0m, groundwater level: H2=17.0m
B. Ground Elevation: H0 = 17.7m, Excavation Trench Bottom Elevation: H3 = 13.4m
C. The natural bulk density weighted average value for soil inside and outside the pit is #r1, r2 both: 20 KN/m³; internal friction angle Φ: 20°; cohesion value c: 0 KPa; void ratio e: 0.89.
D、Ground overload q: 20.0 KN/m².
E. Excavation Depth of Foundation Pit b = 4.3m
2. Support calculation water level is considered at 17.00m.
3. Sheet Pile Calculation
(1) Internal Force Calculation
The calculation of earth pressure in this project considers the active earth pressure entirely borne by the sheet piles as effective active earth pressure. Effective earth pressure at various height points is calculated with a ground elevation of 17.70m as the reference. Overload on the ground is 10KN/m2, which converts to earth height h0=q/γ=10/20=1m.
Active and passive soil pressure coefficients
Safety Precautions for Larsen Sheet Piling Construction
Although the sheet pile is a temporary construction for this project, its construction quality directly affects safety during the construction period. Therefore, we treat it as a permanent structure standard in our construction. The following measures are taken:
1. Steel sheet pile joints must be smooth and tight, with locking edges interlocking properly. Support reinforcement should be secure, ensuring the steel sheets are vertical. Only after the supervisor engineer's approval can excavation of the foundation pit proceed.
2. The project department establishes a construction management organization led by the project manager, with responsibilities assigned to individuals. From raw material procurement to on-site management, every task is supervised, and the person responsible for any issue is held accountable.
3. Strictly adhere to relevant construction specifications and standards, implementing a three-level inspection system internally. Only after the previous process is approved can the next process be carried out.
4. Prior to commencing work, convene the construction team for a technical briefing, ensuring that everyone is familiar with and proficient in the construction procedures and key points. Implement a quality management responsibility system, and any work that does not meet quality requirements must be redone.
5. Ensure proper protection for steel sheet piles, with prominent construction signs in place. Prohibit heavy vehicles from approaching the steel sheet piles to prevent encroachment and ensure construction safety. Additionally, be vigilant during excavation of the foundation pit and strictly prohibit machinery from contacting the steel sheet pile bodies.
6. Take meticulous care of the sheet pile maintenance and prepare spare materials.
7. The foreman will oversee the construction process to ensure orderly progress.


Potential Issues and Solutions in the Construction of Larson Steel Sheet Piling
One, problem with pile driving obstruction
Excessive resistance during pile driving, making it difficult to penetrate.
Reason: Piling in sand or gravel layers; Rusted and deformed steel sheet pile locking slots; Encountering larger obstacles;
Preventive Measures:
1. Conduct a detailed geological analysis to determine the geological conditions within the steel sheet pile penetration depth range.
2. Conduct individual inspections of steel sheet piles prior to桩 driving, removing those with rusted or severely deformed locking sockets, and apply grease within the locking sockets.
3. In cases where larger obstructions such as concrete blocks prevent the installation of steel sheet piles, employ a horseshoe construction method using 3-meter-long and 3-meter-wide piles. If encountering obstacles that cannot be driven, use a long-arm excavator for excavation. Drive the steel sheet piles while挖掘, continuing until they are driven to a depth of 15 meters.
Two: Piling body tilt phenomenon
Reason: During the driving of steel sheet piles, due to the resistance at the locking joint being greater than the resistance around the steel sheet piles, the driving resistance in the direction of the pile's movement is less, causing the pile head to shift towards the direction of less resistance.
Preventive Measures:
1. Continuously inspect, control, and correct the verticality of sheet piles during the construction process using instruments.
2. Gradually correct the tilt by securing the pile body with wire ropes, pulling while hammering.
Section 3: Pile Body Twisting Issue
Reason: The steel sheet pile locking joint is hinged, causing displacement and torsion under the action of insertion and hammering, which then affects the position of adjacent steel sheet piles already driven, resulting in the central axis becoming a zigzag line.
Preventive Measures:
1. Secure the front locking slots of the steel sheet piles with a locking board in the direction of pile driving.
2. Make good use of the guide rail to ensure verticality.
3. In cases of severe twist in the pile shaft, the steel sheet pile in the twisted section can be removed, and then re-drive the piles after implementing the aforementioned measures.
Section 4: Pier-Sinking Issues
Reason: Due to the inclination and bending of the steel sheet piles, the resistance at the connecting locks has increased, causing the adjacent steel sheet piles to sink together.
Preventive Measures:
1. Correct steel sheet piles promptly when they tilt.
2. Weld the sheet pile, which is sinking together, to one or more pieces of shaped steel.
3. Apply grease at the locking hinge to reduce friction.
4. After steel sheet piles sink together, supplemental pieces of the same type should be welded to the top to compensate for any lack of length.
Section 5: Difficulty in Removing Piling
Reason: Rust and severe deformation of the connecting lock; sheet pile driven into dense sand soil layer; insufficient support during excavation, leading to significant deformation of the sheet pile.
Preventive Measures:
1. Hammer the vibration锤 one more time to overcome resistance caused by the adhesion with soil and rust between the striking surfaces.
2. Ripping piles in the reverse order of their installation.
3. The soil on the side bearing earth pressure is denser; driving another sheet pile in parallel near it will allow the original pile to be easily extracted.
4. Side-slot, fill with bentonite slurry, which can reduce resistance during pile removal.


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Sheet pile construction precautions:
Steel sheet pile construction should consider the site characteristics of the project location, combined with the properties of steel sheet piles and construction methods. Lassen IV and VI type steel sheet piles with moderate width and good bending resistance are selected. The length of steel sheet piles is determined based on geological data and working conditions, with specific selection details in the "Foundation Pit Protection Special Technical Briefing." For steel sheet pile construction, there are usually material inspection and appearance inspection, and unqualified steel sheet piles are strictly prohibited from use. To ensure the accuracy of the pile driving axis and the verticality of the piles, control the accuracy of pile driving, prevent the bending deformation of the sheet piles, and improve the penetration ability of the piles, a certain stiffness and sturdy guide frame, also known as "construction cofferdam," is generally required. What should be paid attention to and what technical specifications should be followed during construction? Wuxi Henengyong experts tell you:
On the construction site, it is mandatory to complete "three connections and one leveling." Depending on the site conditions, conditionally lay a ground concrete base layer to facilitate construction. Drainage ditches and stormwater pits should be set up around the site, and accumulated water in the pile holes should be pumped out, sedimentated, and meet environmental protection standards before being discharged into the sewage system. The excavation route at the construction site must be unobstructed. Accurately lay out the lines according to the construction drawings, mark the center line and pile diameter, and conduct a thorough technical review. Only after obtaining a permit from relevant departments can the soil around the pile be excavated. Before digging the pile, four control points from the pile center position to the four sides of the pile should be marked out with sturdy wooden piles.


Prior to steel sheet pile construction, the site technical supervisor and construction staff should inspect the construction preparation for each hole, conduct technical safety briefings and safety education in a tiered manner, ensuring safety and technical management are implemented in terms of thought, organization, and measures. A designated person should be responsible for numbering the pile locations, recording the vertical centerline, axis, pile diameter, pile length, and soil quality of the pile holes; also, hidden acceptance records for reinforcement cages and concrete piles should be compiled and sent to relevant units upon completion, and archived by the technical department. The height of the wall formwork sections should be determined based on soil conditions, generally ranging from 50 to 100 cm. Construction personnel must be familiar with the geological conditions of the holes they are挖掘 and should regularly check, paying attention to changes in soil layers. When encountering flowing sand, excessive groundwater, and other factors that may affect excavation safety, effective protective measures must be taken immediately before continuing with the deep excavation.
Process line measurement and marking → Excavating pile holes → Supporting wall formwork → Pouring wall concrete → Dismantling formwork (these four processes are repeated until the designed depth) → Installing steel cage → Pouring pile concrete.
The hole-plugging ring wall should be 100 to 150mm thicker than the lower wall and should be elevated 200 to 250mm above the ground level or as per design specifications. The overlap length between the upper and lower walls should not be less than 50mm. To ensure the integrity of the concrete wall, reinforcement bars with a diameter of φ8 should be evenly distributed as tie bars to prevent separation and sinking. If there is a detailed design drawing for the wall, construction should be carried out as per the design requirements.
When pouring concrete for the retaining wall, use the method of knocking the formwork and inserting bamboo poles and wooden sticks to compact it. Do not pour concrete when the桩孔 water level submerges the formwork. According to the soil conditions, use rapid-setting agents as much as possible to achieve the design strength requirements as soon as possible. If honeycombing or leakage in the retaining wall is found, block or divert it immediately to prevent water outside the hole from flowing into the hole through the retaining wall, ensuring the strength and safety of the retaining wall concrete. For the installation of each section of the formwork, a designated person should strictly check the center position and thickness of the retaining wall. Use a cross to align the axis mark, suspend a plumb bob at the center of the cross intersection, and recheck the position of the formwork to ensure verticality. After meeting the requirements, use wooden wedges to drive into the soil to support the formwork, stabilize it, and prevent the formwork from moving during concrete compaction. The reinforcing cage made on site should comply with relevant specification requirements.
The removal of the inner formwork for the retaining wall concrete depends on factors such as temperature, etc., and is generally carried out 24 hours later to ensure the concrete has sufficient strength to retain soil. After the formwork for the retaining wall concrete is removed, the axis position is marked on the wall, and the relative level elevation is marked inside the retaining wall using a level, serving as the basis for controlling the position and verticality of the pile hole, and determining the depth and elevation of the pile top. The marked axis position and relative level elevation should be checked and revalidated regularly.
Larson steel sheet piles, as a new type of building material, serve as retaining walls for soil, water, and sand during bridge cofferdams, large pipeline installations, and temporary trench excavations. They also act as protective walls, retaining walls, and embankment revetments at docks and cargo handling areas, playing a crucial role in engineering projects. After the steel sheet pile construction is completed, what should be taken into account when removing the steel sheet piles? Let's listen to the editor of Yanxin Senyu explain these points one by one:
1. Installation and disassembly of pile drivers and auxiliary arms should be conducted on a flat and hard surface.
2. When working in pairs or with a guide, please operate according to the prescribed signal communication.
3. When loading and unloading pile drivers, please use a crane. The hook must have anti-catch devices.
4. Prior to steel sheet pile construction, check daily for loose brakes, hydraulic hoses, and all bolts, nuts, and pins. Inspect the drilling rig's oil (lubricant) level and for leaks.
5. Assembly and disassembly of the auxiliary arm, by hydraulic excavatorThe essentials for the installation and removal of excavator buckets.
6. Please inspect if the jaw tooth blocks are excessively worn.
7. Please regularly clean the accumulated soil at the top of the pile. Do not remove it if the pile head is deformed.
8. When handling hydraulic pipes and connectors, please ensure the engine of the hydraulic excavator is turned off and wait until the internal pressure of the hydraulic system is released before proceeding. If internal pressure remains, oil leakage may occur. For methods to release internal pressure, refer to the "Operation Manual" issued by the hydraulic excavator manufacturer.
9. In handling hydraulic hoses, if leakage comes into contact with skin or eyes during high-pressure operation, it poses a significant danger. Therefore, please wear protective goggles and thick gloves. In case of high-pressure oil喷射, block the nozzle with a plug and take measures to stop the spray.
10. Do not turn on the equipment before replacing the worn-out shock-absorbing rubber.
This concludes the key points to consider during the removal of sheet pile installation, as introduced by Yanxin Senyu. Yanxin Senyu adheres to the guiding principle of "technology-driven factory," with a commitment to "quality and customer first." We possess extensive experience in sheet pile installation, superior equipment processing and manufacturing capabilities, and are fully equipped to design and fabricate various Lasen sheet piles based on special customer requirements. We look forward to a sincere and cooperative partnership, creating great achievements together.
On the construction site, "Three Connections and One Leveling" must be ensured. Concrete lining work should be done first according to the ground conditions on-site for convenience. Drainage ditches, wastewater pits, sedimentation holes should be set up around the site to meet environmental protection requirements before discharge into the sewers. The route for removing soil from the site should be kept clear. Accurately lay out according to the plans, release the centerline pile positions and diameters, and undergo technical review for excavation through relevant procedures. Before digging pile holes, piles will be stacked at the center, with four control points at the heart of each side, marked with wooden piles.
 
Before steel sheet pile construction, technical personnel and construction workers on the construction site should undergo a hole construction preparation inspection, step-by-step technical testing, safety education, and safety measures. Technical management is organized in thought and action, and the measures are implemented. The person responsible for the pile location prepares the pile hole axis, pile diameter, pile length, and vertical center line of the bedrock soil records; the concealed acceptance records for the pile reinforcement cage and concrete are made, and the related units are organized for knitting and the books are issued, and then sent to the technical department for filing. According to soil conditions, the wall formwork is divided into heights, usually 50 to 100 centimeters. It is necessary to be familiar with the excavation of geological conditions by construction personnel, and to check frequently. When facing a large amount of groundwater affecting the safety of excavators, pay attention to soil changes, and after flowing sand, take effective protective measures immediately before continuing to excavate deeper.
 
The excavation process should have higher retaining wall thickness than that of holes with a wall thickness less than 100-150mm, and the site should be elevated 200-250mm above the ground or as per design requirements. The overlap length between the upper and lower stop walls should not be less than 50mm. To ensure the integrity of the steel sheet pile retaining wall, considering soil conditions, we must use a uniform arrangement of φ8 rebar tie rods to prevent sinking and disconnection, as per the design requirements for large-scale painting wall construction.
 
When pouring concrete walls, use the actual interlacing method with bamboo poles and wooden sticks for formwork and striking. Do not fill concrete when the formwork is submerged in the pile holes. Depending on soil conditions, try using accelerators to reach the design strength requirements as quickly as possible. Detect honeycombs, leaks, blockages, or shifts promptly to prevent water from seeping into external holes on the wall's perimeter, ensuring the concrete's strength and safety. With each part of the formwork installation, have someone else strictly check the center position and wall thickness, ensuring the template's position by aligning the center of the plumb bob with the axis marked for the cross-hanging line. For those meeting requirements, use wedges to support the formwork in a stable position to prevent the displacement of concrete pounds. When fabricating steel cages on-site, adhere to relevant regulatory requirements.
 
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