Larson steel sheet piles are a type of construction material featuring interlocking devices at both ends, allowing them to be connected with other plates. The connected 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, and excellent waterproofing properties; durability with a service life of 20-50 years; and reusability, typically used 3-5 times. They also exhibit significant environmental benefits, significantly reducing the amount of soil excavation and concrete used during construction, effectively protecting land resources. In fact, Larson steel sheet piles have strong disaster relief capabilities, particularly in flood prevention, landslide, subsidence, and shifting sand rescue efforts, where they show rapid results. Of course, their simplicity in construction, shortened project duration, lower construction costs, and immunity to weather conditions are major advantages. During use, they can simplify the complex procedures of inspecting materials or system performance; ensuring good adaptability and interchangeability. Below, the editor from Xianji website will introduce the knowledge of Larson steel sheet piles, including construction techniques, precautions, potential issues, and their solutions. Check it out!
Larson steel sheet pile construction technique
The construction process is as follows: survey and layout → construction piles → installation of frames → driving steel sheet piles → excavation of foundation pit to subgrade bottom → setting up drainage system → backfilling → removal of steel sheet piles.
One. Survey and Stake Out
Prior to excavation, lay out the centerline of the wastewater pipeline and the excavation boundary according to the coordinates and dimensions shown in the drawings. Establish temporary benchmark levels for elevation control during pipeline construction. The centerline should be marked on both end posts for easy checking. The measurement and layout must be verified by the supervising engineer before proceeding to the next stage of construction.
Two, construction pile
Measure the orientation and lay out the position for the insertion of the Larsen steel sheet piles. Utilize a crawler-mounted hydraulic single-drum vibratory pile driver (with clamps), first driving piles at intervals of approximately 9 meters, setting one Larsen pile each time. Place a crossbar between two piles to create a guide clamp. During the sinking process, the crane delivers the vibration box to the storage area of the steel sheet piles, fits the pile into the clamp, and tightens it. Then, hoist it to the sinking position, vertically insert it into the pile hole, check for accuracy, and proceed to sink the pile using the vibratory hammer.
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, the pile is clamped into the clamp, then 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.
Four: Driven steel sheet piles
1. During pile driving, the crane delivers the vibration box to the steel sheet pile storage area, fits the steel sheet pile into the pile clamp and secures it, then hoists it to the pile driving position, vertically inserts it into the pile hole, checks for accuracy, and then starts the vibration hammer to drive the pile.
2. During the vibration insertion into the soil layer, if encountering underground debris and small stone sand particles, you can vibrate and lift the sheet pile to remove them before reinserting. Repeat this up-and-down vibration insertion multiple times until it is fully inserted. During the pile driving process, pay attention to controlling the descent speed of the hook to maintain the suspended state of the pile driving, ensuring the verticality of the pile.
3. On-site personnel must follow instructions. When lifting 9m steel sheet piles, the rope must be secured at a stable part between 1.8m and 1m on the sheet pile to prevent malfunction and slippage. The operator of the control box should closely monitor the crane's rotation direction, tighten each pile securely, and regularly check the rope to prevent damage and avoid accidents.
4. After the Larsen steel sheet pile and anchor piles are driven, weld steel brackets above the Larsen piles to support and secure the steel sheeting and焊接 cross bracing for additional tensile reinforcement.
5. Excavation of Foundation Trench
1. Primary Equipment:
A. Earthmoving equipment includes excavators, dump trucks, and more.
B. Standard equipment includes: shovels (with pointy and flat heads), hand trucks, white wire or #20 wire绳, and steel measuring tapes.
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 construction plan requirements.
B. The location control lines (stakes) or boundaries of the building site, standard level stakes, and the white line dimensions of the trenching must be inspected and approved; pre-inspection procedures must be completed.
C. When working at night, adequate lighting facilities must be provided; clearly marked signs should be set up in hazardous areas, and the excavation sequence should be arranged reasonably to prevent incorrect or excessive excavation. The excavated soil should be transported to the disposal 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 if necessary, as preparatory measures.
E. In areas where mechanical construction cannot be performed, such as grading the slope, cleaning the bottom of the pit, etc., all work should be carried out in collaboration 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, a single-pass excavation method must be used during mechanical excavation. Layer-by-layer excavation is not feasible as the excavator cannot rotate at the layer position to remove soil. Continuously measure the foundation pit edge line and base elevation to ensure soil is in place without over-excavation, leaving a 10cm clearance for manual cleanup.
G. Prevent excavator from impacting piles and disturbing the bearing layer of the foundation.
H. Establish temporary drainage ditches and a collection well inside and outside the foundation pit (1m from the edge), and assign a dedicated person to handle drainage.
Section 6: Drainage System Setup
Based on geological survey data, the ground water level at this site is high, and groundwater is visible during the local excavation process. Therefore, appropriate drainage and water reduction measures must be taken before and during the excavation to ensure the safety of the foundation pit construction. Temporary ditches, water reduction wells, and sedimentation ponds should be set up around the foundation pit to promptly discharge the water.
2. Four 100mm pumps are used for water extraction within the foundation pit, with an additional 15 50mm pumps for dewatering wells and 5 spare 50mm pumps on standby.
Section 7: Refilling
Upon completion of the wastewater pipeline construction and reaching the backfill condition, clean up the debris in the foundation pit. Use medium to coarse sand that meets the design requirements for layered compaction and water-tight backfill, proceeding from one end to the other in layers from bottom to top. During backfilling, attention should be given to protect the structure from damage.
8. Remove steel sheet piles
1. Excavation backfilling must be completed before removing the steel sheet piles, and the piles are to be lifted using a 20-ton crawler crane.
2. Prior to removing the piles, the gaps between the steel sheet piles must be filled back in.
3. When removing each steel sheet pile, ensure the retrieval rope is properly tensioned, keeping the hook vertical 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 removal, assign personnel for monitoring. If the monitor issues a warning, the pile removal must be slowed down or paused, and resumed only after appropriate measures have been taken.
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 weighted average bulk density of soil inside and outside the pit is #r1, r2 both: 20 KN/m3. The internal friction angle Φ: 20°; cohesion value c: 0 KPa; void ratio e: 0.89.
D、Ground overloading 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. Steel Sheet Piling Calculation
(1) Internal Force Calculation
The soil pressure calculation for this project considers the active soil pressure supported by the steel sheet piles as effective active soil pressure. Taking the ground elevation of 17.70m as the reference, the effective soil pressure at various height points is calculated. The ground superload is 10KN/m2, which is converted to soil height h0 = q/γ = 10/20 = 1m.
A. Active and passive earth pressure coefficients
Safety Precautions for Larson Steel Sheet Piling Construction
Although the steel sheet pile is a temporary structure in this project, its construction quality directly affects safety during the construction period. Therefore, we treat it as a permanent structure standard in our construction. To this end, we implement the following measures:
1. Steel sheet pile joints must be smooth and tight, with locking edges interlocking, and the support reinforcement must be secure to ensure the steel plates are vertical. The sheet piles, after being properly set up, must pass the inspection by the supervising engineer before excavation of the foundation pit can proceed.
2. The project department establishes a construction management organization led by the project manager, assigning responsibilities to individuals. This ensures that from raw material procurement to on-site management, every aspect is supervised, and the responsibility of the person in charge is pursued if any issue arises.
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 commencement, convene the construction team for a technical briefing, ensuring that everyone is familiar and proficient with the construction procedures and key points. Implement a quality management responsibility system, and any work not meeting quality requirements must be redone.
5. Ensure proper protection for sheet pile, with prominent construction signs in place. Prohibit heavy vehicles from approaching the sheet pile to prevent encroachment and ensure construction safety. Additionally, be vigilant during excavation of the foundation pit and strictly prohibit machinery from contacting the sheet pile.
6. Take careful maintenance of the sheet pile and prepare spare materials.
7. The foreman will oversee the construction process to ensure it proceeds smoothly.


Potential Issues and Solutions in the Construction of Larson Sheet Pile
One: Piling Obstacle Issue
Excessive resistance during pile driving makes it difficult to penetrate.
Reason: Piling in sand or gravel layers; Corrosion and deformation of steel sheet pile locking joints; Encountering large obstacles;
Preventive Measures:
1. Conduct a detailed geological analysis to determine the geological conditions within the penetration depth range of the steel sheet piles.
2. Inspect each steel sheet pile before driving, removing those with rusted or severely deformed locking clips, and apply grease within the locking clips.
3. In cases where larger obstacles like concrete blocks prevent the use of steel sheet piles, employ a figure-8 construction method with 3-meter-long and 3-meter-wide sections. If obstacles prevent installation, use a long-arm excavator to dig through. Continue driving the sheet piles while excavating, until they reach a depth of 15 meters.
Two,桩身倾斜 phenomenon
Reason: During the driving of sheet pile, due to the greater resistance at the connection lock joint compared to the surrounding area of the sheet pile, the resistance against penetration in the direction of movement of the pile is reduced, causing the head of the sheet pile to displace towards the direction of lesser resistance.
Preventive Measures:
During construction, use instruments to regularly inspect, control, and correct the verticality of sheet pile.
2. Gradually correct the tilt by securing the pile body with steel wire rope, pulling while hammering.
Section 3: Pile Body Twisting Issue
Reason: The sheet pile locking joints are articulated, which can cause displacement and torsion under the action of insertion and hammering. This movement affects the position of adjacent sheet piles already driven, resulting in a wavy central axis.
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 piles in the twisted section can be removed, and after implementing the aforementioned measures, the piles can be driven again.
Section 4: Piling Submersion Issues
Reason: Due to the inclined and bent steel sheet piles, the resistance at the connection lock increases, causing adjacent steel sheet piles to sink together.
Preventive Measures:
Correct steel sheet piles promptly when they begin to tilt.
2. Weld the sheet pile with the attached down-angled steel to one or several pieces of shaped steel.
3. Apply grease at the locking mouth to reduce resistance.
4. After the steel sheet piles are submerged together, supplementary steel sheet piles of the same type should be welded to their heads to compensate for the insufficient length.
Difficulty in Piling Removal
Reason: Rust and severe deformation of the locking mouth; sheet pile driven into compacted sand soil layer; insufficient support during excavation, resulting in significant deformation of the sheet pile.
Preventive Measures:
1. Re-tamp the vibration hammer to overcome resistance caused by the adhesion to soil and rust between the hammer and the mouth.
2. Piling extraction in reverse order of the driving sequence.
3. The soil on the side bearing earth pressure is denser; driving another sheet pile alongside it can facilitate the easy extraction of the original pile.
4. Side slot, pour in bentonite slurry, resistance can be reduced during pile removal.


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Steel sheet pile construction precautions:
Steel sheet pile construction takes into account the site characteristics of the engineering location, combining the properties of steel sheet piles and construction methods. The width of Larsen IV and VI steel sheet piles is moderate with good flexural performance. The length of steel sheet piles is determined based on geological data and working conditions, with specific selection details in the "Special Technical Instructions for Foundation Pit Protection." For steel sheet pile construction, general material inspection and外观 inspection are required, and unqualified steel sheet piles are strictly prohibited. To ensure the correct alignment and verticality of the piles during construction, control the accuracy of pile driving, prevent buckling deformation of the sheet piles, and enhance the penetration ability of the piles, it is generally necessary to set up a certain degree of rigidity and sturdy guide frames, also known as "construction bracing." So what are the matters and technical specifications to be aware of during construction? The experts at Wuxi Hengyong can inform you:
On the construction site, "Three Connections and One Leveling" must be properly implemented. Depending on the site conditions, it is advisable to first lay a ground concrete base to facilitate construction. Drainage ditches and sedimentation ponds should be set up around the site, and accumulated water in the pile holes should be pumped out, treated, and meet environmental protection standards before being discharged into the storm drain. The出土 route on the construction site should be kept clear. The lines should be accurately laid out according to the construction drawings, marking the pile center lines and diameters, and a thorough technical review should be conducted. Only after obtaining a permit from the relevant authorities can excavation of the pile soil begin. Before digging the pile, four control points for the pile center should be marked out to the four sides of the pile using sturdy wooden stakes.


Before the steel sheet pile construction, the technical person in charge of the construction site and the construction staff should inspect the construction preparation for each pile hole, conduct technical safety briefings and safety education step by step, ensuring that safety and technical management are implemented in terms of thought, organization, and measures. A designated person should be responsible for numbering the pile positions, recording the vertical centerline, axis, pile diameter, pile length, and soil quality of the pile holes; hidden acceptance records for steel cage and concrete piles, and compile and distribute them to relevant units after completion, and send them to the technical department for filing. The height of the wall formwork sections should be determined based on the 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 they should check frequently, paying attention to changes in soil layers. When encountering flowing sand, excessive groundwater, and other factors that affect soil excavation safety, effective protective measures must be taken immediately before continuing to excavate deeper.
Process line measurement and layout → Excavation of pile holes → Support wall formwork → Pouring support wall concrete → Demolishing formwork (these four processes are repeated until the designed depth) → Installation of steel cage → Pouring pile concrete.
The operation process for the hollowing and hole-cutting of the wall should be 100-150mm thicker than the lower wall, and it should be elevated 200-250mm above the ground level or as per design requirements. The overlap length between the upper and lower walls should not be less than 50mm. To ensure the integrity of the wall concrete, depending on the soil condition of the wall, φ8 rebars should be uniformly distributed as tie rods to prevent separation and sinking. If the design includes a detailed drawing of the wall, construction should be carried out as per the design specifications.
During the pouring of concrete for the retaining wall, use the method of striking 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 reach the design strength requirements quickly. In case of honeycomb or leaking in the retaining wall, promptly block or divert them to prevent water from 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 person should be designated to strictly check the center position and the thickness of the retaining wall. Use a cross to align the axis marks, suspend a plumb bob at the center of the cross intersection, and recheck the position of the formwork to ensure its verticality. After meeting the requirements, use wooden wedges to drive into the soil to support the formwork, stabilize it, and prevent the formwork from shifting during concrete compaction. The reinforcing cage made on-site should comply with relevant specification requirements.
Demolition of the inner formwork of the retaining wall concrete depends on factors such as temperature, etc., and is generally carried out after 24 hours. This allows the concrete to gain sufficient strength to support soil. After the formwork of the retaining wall concrete is removed, the axis position is marked on the retaining wall, and the relative level elevation is marked within the retaining wall using a level. This serves as the basis for controlling the position and verticality of the桩孔, as well as determining the depth and elevation of the pile top. The marked axis position and relative level elevation should be frequently checked and verified.
Larson steel sheet piles, as a new type of building material, play a crucial role in bridge cofferdams, large pipeline installations, and temporary trench excavations by serving as retaining walls for soil, water, and sand. They also act as protective walls, retaining walls, and embankment revetments at docks and cargo handling sites. After the steel sheet pile construction is completed, what should be taken into consideration when removing the piles? Let's listen as the editor of Yanxin Senyu explains each point for you:
1. Installation and dismantling of pile drivers and auxiliary arms should be performed on a flat and hard surface.
2. When working with two or more individuals or with a guide, please operate according to the prescribed signal for communication.
3. When loading and unloading pile drivers, please use a crane. The hook must have a anti-catch device.
4. Prior to steel sheet pile construction, check daily for loose motor brakes, hydraulic hoses, and bolts, nuts, pins, etc. in all parts. Inspect the oil (lubricant) level and leaks in the pile driver.
5. Assembly and disassembly of the auxiliary arm, by hydraulic excavatorThe installation and removal techniques for excavator buckets are conducted.
6. Please inspect if the jaw cheek blocks are excessively worn.
7. Please regularly clean the accumulated soil at the pile head. Do not remove any deformation at the pile head.
8. When loading or unloading hydraulic pipes and connectors, please turn off the engine of the hydraulic excavator first. Perform the operation after the internal pressure of the hydraulic system has been relieved. If there is still internal pressure, oil leakage may occur. For methods to relieve internal pressure, refer to the "Operation Manual" issued by the hydraulic excavator manufacturer.
9. In handling hydraulic hoses, if leakage of high-pressure oil comes into contact with skin or eyes, it poses a danger. Therefore, please wear protective eyewear and thick gloves. In case of high-pressure oil being sprayed, block the nozzle with a plug and take measures to stop the spray.
10. Do not turn on the equipment until new shock-absorbing rubber is installed, as cracking has occurred in the existing rubber.
Here are the key points to consider when removing sheet pile during construction, as introduced by Yanxin Senyu. Yanxin Senyu adheres to the guiding principle of "technology-driven factory" and is committed to "quality and customer-first." With extensive experience in sheet pile construction and excellent equipment processing capabilities, we are fully capable of designing and manufacturing various Lassen sheet piles based on the special requirements selected according to customer needs. We are eager to collaborate with you sincerely and create great achievements together.
On the construction site, "three connections and one leveling" must be ensured. Concrete lining construction should be done first, based on the ground conditions on site. 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 excavation on the site should be kept clear. Line up accurately according to the drawings, release the centerline pile position and pile diameter, and undergo technical review for excavation of piles through relevant procedures. Before digging the bore piles, the piles will be stacked at the center position, with four heart points on the sides, marked with wooden piles.
 
Before the steel sheet pile construction, technical personnel and construction workers on the construction site should undergo a hole construction preparation check, step-by-step technical testing, safety education, and safety measures. Technical management is organized in thought and action, and 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 steel cage and concrete are issued to related units, and then sent to the technical department for filing. According to soil conditions, the wall formwork is divided at a height of 50 to 100 centimeters. It is necessary to be familiar with the excavation of the geological conditions by the construction personnel, and to frequently inspect. When facing a large amount of groundwater affecting the safety of excavators, pay attention to soil changes, after the flowing sand, immediately take effective protective measures, and continue excavation after deepening.
 
The excavation process should have a higher retaining wall thickness than the 100-150mm季度 hole wall, and the site should be elevated by 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 the soil conditions, we must use a uniform arrangement, φ8 reinforcing steel tie rods, to prevent settlement and disconnection, as per the design requirements of large-scale painting wall construction.
 
When pouring concrete walls, use the actual interlacing method with bamboo sticks and wooden rods for formwork and percussion. Do not fill concrete when the formwork in the pile holes is submerged. Depending on soil conditions, try using accelerators to reach the design strength requirements as soon as possible. Discover honeycombs, leaks, clogs, or shifts promptly to prevent water from flowing into the external holes of the wall, ensuring the concrete wall's strength and safety. For every part of the formwork installation, have someone else strictly inspect the center position and wall thickness, ensuring the template's position by looking through the cross-hanging plumb line marked by the alignment axis. For those meeting requirements, use wooden wedges to support the formwork in a stable position to prevent the displacement of concrete pounds. When manufacturing reinforcing cage on-site, follow the relevant regulatory requirements.
 
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