Larson steel sheet piles are a type of construction material with interlocking devices at both ends, allowing them to be connected with other panels. The connected steel sheet wall can serve as a safe support, water barrier, and sand barrier in water or underground. Due to its unique structure, it boasts distinct advantages: high strength, light weight, excellent water resistance; durability with a lifespan of 20-50 years; and reusability, typically for 3-5 cycles. They offer significant environmental benefits, reducing the amount of soil excavation and concrete used during construction, effectively protecting land resources. In fact, Larson steel sheet piles are also highly effective in emergency rescue operations, particularly in flood prevention, landslides, collapses, and sand erosion. Their simplicity in construction, shortened project timelines, and lower construction costs, not to mention being不受weather constraints, are major advantages. 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, and their solutions. Take a look!
Larson steel sheet pile construction technique
The construction process is as follows: measurement and line laying → construction pile installation → frame assembly → steel sheet piling insertion and driving → excavation to the sub-base level → drainage system setup → backfilling → removal of steel sheet piling.
One, Measurement and Staking Out
Prior to excavation, lay out the centerline of the sewage pipeline and the excavation boundary according to the coordinates and dimensions shown in the drawings. Establish temporary benchmark levels for elevation control during the pipeline construction. The centerline should be marked on both end posts for easy checking. The surveying and layout must be reviewed and confirmed by the supervising engineer before proceeding to the next stage of construction.
Two, construction piles
Measure the designated orientation and lay out the lines, determining the insertion positions for the Larsen steel sheet piles. Utilize a crawler-type hydraulic single-bucket vibratory pile driver (with clamps), first driving piles at intervals of approximately 9 meters, installing one Larsen pile each time. Place a horizontal bar between the two middle piles to create a guide clamp. During the sinking process, the crane transports 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 with the vibratory hammer.
Section 3: Installation Rack
A steel pile is placed horizontally between two piles to make a guide clamp. During pile driving, the vibration box is moved to the storage area of the steel piles, the steel pile is inserted into the clamp and tightened, then hoisted to the pile driving position, vertically inserted into the pile hole, and after checking for correctness, the vibration hammer is activated to drive the pile.
Section 4: Driven steel sheet pile
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, 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. When vibrating the sheet pile into the soil layer, if encountering underground debris and small stone sand particles, you can vibrate and lift the pile to remove them before reinserting. Repeat this up-and-down vibration insertion multiple times until 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 sinking, ensuring its verticality.
3. On-site staff must follow instructions. When lifting 9m steel sheet piles, the rope must be securely fastened at the 1.8m to 1m solid 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 individually, and frequently inspect the rope to prevent damage and accidents.
After driving the Larsen steel sheet pile and anchor piles, weld steel haunches at the top of the Larsen piles, and place and secure steel sheeting, then weld cross bracing for reinforcement.
V. Excavation of Foundation Trench
1. Primary Equipment:
A. Excavating equipment includes excavators, dump trucks, etc.
B. General equipment includes: shovels (both pointed and flat heads), hand carts, small white wire or 20# galvanized 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 (piles) of the building or site, the standard level piles, and the dimensions of the white lines for trenching must pass inspection and be deemed qualified; pre-inspection procedures must also be completed.
C. When working at night, adequate lighting facilities should be provided; at hazardous locations, clear signs should be set up, and the excavation sequence should be arranged reasonably to prevent incorrect or excessive excavation. The excavated soil 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 necessary preparations such as reinforcement or widening should be made.
E. In areas where mechanical construction cannot be performed, and for tasks such as adjusting the slope of the embankment and cleaning the bottom of the pit, manual labor should be utilized in conjunction.
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 to prevent the excavator from rotating in the layer during layered excavation. Continuously measure the foundation pit edge line and base elevation to ensure the soil is in place without over-excavation, and leave a 10cm allowance for manual cleanup.
G. Prevent excavator impact on piles and disturbance of the base bearing layer.
H. Install temporary drainage ditches and a sedimentation well inside and outside the foundation pit (1m from the edge of the pit), and assign a dedicated person to handle the drainage.
Section 6: Drainage System Setup
1. Based on geological survey data, the groundwater level at this site is high, and groundwater is visible during the local excavation process. Therefore, appropriate drainage and water lowering measures must be taken before and during the foundation pit excavation to ensure the safety of the construction. Temporary ditches, water lowering 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 excavation pit. An additional 15 50mm pumps are equipped for water extraction from the dewatering wells, with 5 spare 50mm pumps on standby.
Section 7: Refilling
Upon completion of the wastewater pipeline construction and reaching the backfilling condition, clean the foundation pit debris. Use medium to coarse sand that meets the design requirements for layered compaction and water-tight backfilling, starting from one end to the other, 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; pile removal is done using a 20T crawler crane for lifting.
2. It is mandatory to backfill the gaps between steel sheet piles before removing them.
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 up a truck, return an empty one, and maintain the cleanliness of the construction site.
4. Assign personnel to monitor the pile removal process. If the monitor issues a warning, the pile removal speed must be slowed down or the process must be paused until appropriate measures are taken before resuming.
Section 9: Simplified Calculation of Steel Sheet Piling Load
Based on the soil stratum descriptions provided in the geological data from the design drawings, the soil parameters in this calculation are determined as follows by experience:
A. Sheet pile top elevation: H1=18.0m, groundwater level: H2=17.0m
B. Ground Elevation: H0 = 17.7m, Excavated 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. 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 Piling Calculation
(1) Internal Force Calculation
The soil pressure calculation for this project considers the active soil pressure borne by the steel sheet piles as the effective active soil pressure. The effective soil pressure at various elevation points is calculated with a ground elevation of 17.70m as the reference. The ground surcharge is 10KN/m2, which converts to a soil height h0 = q/γ = 10/20 = 1m.
Active and passive soil pressure coefficients
Safety Precautions for Larsen Sheet Piling Construction
Although the steel sheet pile is a temporary construction for this project, the quality of its installation directly affects safety during construction. Therefore, we treat it as a permanent structure in terms of construction standards and implement the following measures:
1. Steel sheet piles must be joined smoothly and tightly, with locking lips interlocking, and the support reinforcement must be secure to ensure the verticality of the steel plates. The steel sheet piles, after being inspected and approved by the supervising engineer, can then proceed with excavation of the foundation pit.
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-tier inspection system internally. Only after the prior stage is approved can the next stage of construction proceed.
4. Prior to commencement, convene the construction crew 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 steel sheet piles, and set prominent construction signs. 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 body.
6. Ensure proper maintenance of sheet pile and have backup materials ready.
7. The foreman will oversee and coordinate the construction process to ensure it proceeds smoothly.


Potential Issues and Solutions in Larsen Sheet Piling Construction
One: Obstacle in Piling Operation
Excessive resistance encountered during pile driving, making it difficult to penetrate.
Reason: Piling in sand or gravel layers; Corrosion and deformation of steel sheet pile locking clips; Encountering large obstacles;
Preventive Measures:
1. Conduct a detailed geological analysis to determine the conditions within the penetration depth range of the steel sheet piles.
2. Inspect each sheet pile before driving, remove those with rusted and severely deformed locking sockets, and apply grease within the locking sockets.
3. In cases where larger obstructions like concrete blocks prevent the installation of steel sheet piles, employ a horseshoe construction method using 3-meter long and 3-meter wide piles. If obstacles prevent driving, 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.
II. Pier Tilting Phenomenon
Reason: During the driving of sheet pile, due to the resistance at the connection lock mouth being greater than the resistance around the sheet pile, the driving resistance in the direction of the pile movement is smaller, causing the head of the sheet pile to displace 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 with a wire rope, pulling as you hammer.
Section 3: Pile Body Twisting Issue
Reason: The steel sheet pile lock is hinged, which, under the action of insertion and hammering, will cause displacement and torsion, affecting the position of adjacent sheet piles already driven, resulting in the central axis line becoming a zigzag shape.
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 then re-driving the piles after implementing the aforementioned measures.
Four: Pile Submersion Issue
Reason: Due to the inclination and bending of the steel sheet piles, the resistance at the connection lock increases, causing 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 port to reduce resistance.
4. After the sheet pile is submerged, supplement its insufficient length by welding the same type of sheet pile to its head.
Section 5: Difficulty in Piling Removal
Reason: Rust and severe deformation of the locking mouth; steel sheet piles driven into compacted sand soil layer; insufficient support during excavation, resulting in significant deformation of the steel sheet piles.
Preventive Measures:
1. Strike the vibration hammer again to overcome resistance caused by the adhesion to soil and rust between the hammer and the mouth.
2. Driving piles in the reverse order of extraction.
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, insert bentonite slurry, can reduce resistance during pile pulling.


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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. Choose Larsen IV and VI steel sheet piles with moderate width and good bending resistance. The length of the steel sheet piles is determined based on geological data and working conditions. Specific selection of steel sheet piles is detailed in the "Foundation Pit Protection Special Technical Handover." For steel sheet pile construction, general material inspections and外观 inspections are required; unqualified steel sheet piles are strictly prohibited. To ensure the correct position of the pile centerline and the verticality of the piles during construction, control the accuracy of pile driving, prevent the bending deformation of the sheet piles, and improve the penetration capacity of the piles, it is generally necessary to set up a certain degree of rigidity and sturdy guide frames, also known as "construction railings." So, what should be paid attention to and what technical specifications should be followed during construction? Wuxi Hengyong experts inform you:
On the construction site, "Three Connections and One Leveling" must be ensured. Depending on the on-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 the accumulated water in the pile holes should be pumped out, settled, and meet environmental protection standards before being discharged into the sewers. The route for removing soil from the construction site must be kept clear. Accurately lay out the construction drawings, mark the center line and diameter of the pile, and conduct a technical review meticulously. Only after obtaining a permit from the relevant authorities can excavation of the pile soil begin. Before挖掘the pile, four control points at the center of the pile should be marked out to the four sides of the pile using sturdy wooden stakes.


Prior to steel sheet pile construction, the technical supervisor and construction staff on the construction site should inspect the construction preparation for each pile hole, conduct technical safety briefings and safety education in a step-by-step manner, ensuring that safety and technical management are implemented in terms of thought, organization, and measures. A designated person should be responsible for recording the vertical centerline, axis, pile diameter, pile length, and foundation soil quality according to the pile position numbers; hidden acceptance records for reinforcement cages and concrete piles, etc., should be compiled and sent to relevant units after completion, and archived by the technical department. 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 regularly inspect and pay attention to changes in soil layers. When encountering issues like flowing sand, excessive groundwater, and other factors that affect excavation safety, effective protective measures must be taken immediately before continuing with the deep excavation.
Process measurement and layout → Excavation of pile holes → Support wall formwork → Pouring of support wall concrete → Demolition of formwork (these four processes are repeated until the designed depth) → Installation of steel cage → Pouring of pile concrete.
The excavation wall with holes should be 100-150mm thicker than the lower wall and should be elevated 200-250mm 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 wall concrete, reinforcement bars with a diameter of φ8 should be evenly distributed as tie bars to prevent disconnection 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 side formwork, use the method of tapping 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. Depending on the soil conditions, try to use rapid-setting agents to achieve the design strength requirements as soon as possible. If honeycomb or leakage is found in the side formwork, promptly plug or divert it to prevent water from outside the hole from flowing into the hole through the side formwork, ensuring the strength and safety of the concrete. For each section of the formwork installation, a designated person should strictly check the center position and thickness of the side formwork. Use a cross to align the axis mark, hang a plumb bob at the center of the cross, recheck the position of the formwork, and ensure the verticality. After meeting the requirements, wooden wedges can be driven into the soil to support the formwork, stabilize it, and prevent displacement of the formwork 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 after 24 hours to ensure the concrete has sufficient strength for soil retention. 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 perimeter with a level instrument, serving as a reference for controlling the pile hole position and verticality, as well as determining the depth and elevation of the pile cap. The marked axis position and relative level elevation should be frequently checked and re-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, serving as retaining walls for soil, water, and sand. They act as guardrails, retaining walls, and embankment protection at docks and cargo areas. After the steel sheet pile construction is completed, what should be taken into consideration when removing the steel sheet piles? Let's listen as the Yanshen Senyu editor explains each point in detail:
1. Installation and disassembly of pile drivers and auxiliary arms should be conducted on a flat and hard surface.
2. When two or more individuals, or with a guide, are working together, please operate according to the prescribed communication signals.
3. When loading and unloading pile drivers, please use a crane. The hook must have anti-catch devices.
4. Prior to steel sheet pile installation, inspect the motor brake, hydraulic pipes, and all bolts, nuts, pins, etc., daily for looseness. Check the oil level (lubricant) in the pile driver and for leaks.
5. Assembly and disassembly of the auxiliary arm, by hydraulic excavatorInstallation and removal techniques for excavator buckets.
6. Please inspect if the jaw cheek blocks are excessively worn.
7. Please regularly clean off accumulated soil from the桩head, but do not remove it if the桩head is deformed.
8. When loading or unloading hydraulic pipes and connectors, please ensure the engine of the hydraulic excavator is turned off. Proceed only after the internal pressure of the hydraulic system has been released. 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 high-pressure oil leakage comes into contact with the skin or eyes, 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 machine for use before replacing the vibration damping rubber when it cracks.
Here are the key points to note when removing steel 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 steel sheet pile construction and excellent equipment processing and manufacturing capabilities, we are fully capable of designing and manufacturing various Lassen steel sheet piles based on specific customer requirements. We eagerly look forward to a sincere and cooperative partnership to create great achievements together.
On the construction site, "Three Connections and One Leveling" must be ensured. Concrete lining work should be done first based on the ground conditions. Drainage ditches, wastewater pits, sedimentation holes should be set up around the site to meet environmental protection requirements before discharge into the sewage system. The route for excavation on the site should be kept clear. Align accurately according to the drawings, release the centerline pile position and pile diameter, and undergo technical review for excavation through relevant procedures. Before bore pile excavation, the pile will be stacked at the center, with four heart points on all sides to form four control points, marked with wooden piles.
 
Before 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 the measures are implemented. The person responsible for the pile position makes the pile hole axis, pile diameter, pile length, and vertical center line of the bedrock soil records; hidden acceptance records for the pile steel cage and concrete, and knit the relevant units for book distribution and send them to the technical department for filing upon completion. 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 the geological personnel, and to check frequently, paying attention to soil changes when facing large amounts of groundwater affecting the safety of the excavator, flowing sand, and immediately taking effective protective measures before continuing to excavate deeply.
 
The excavation process should have a higher retaining wall thickness than the 100-150mm quarterly hole wall, and the site should be elevated 200-250mm above 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 of φ8 rebars for tie-backs to prevent settlement and disconnection, as per the construction design requirements.
 
When pouring concrete for wall forms, use the actual interlacing method with bamboo poles and wooden sticks. Do not fill concrete when the formwork is submerged in pile holes. Depending on soil conditions, try using accelerators to reach the design strength requirements as soon as possible. Promptly identify honeycombs, leaks, blockages, or shifts in the Great Wall to prevent water from entering the external holes of the wall, ensuring the concrete strength and safety. For each part of the formwork installation, have someone else strictly check the center position and wall thickness, ensuring the template is aligned by passing a plumb bob over the center of the aligned axis, and verify the verticality. For those that meet requirements, use wooden wedges to support the formwork in a stable position to prevent the displacement of concrete pounds. When making reinforcing cages on-site, follow the relevant regulatory requirements.
 
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