Special safety plan Special plan for wooden piles

The lower section of the old main course of the Yellow River in Huai'an City (the section from Erhe to Lianshui Stone

Lake) management project construction standard I

Wood

Pile

Construction

Project

Plan

Plan

Approval: Review: Preparation:

Jiangsu Huaiyin Water Conservancy Construction Co., Ltd.

Huai'an City Yellow River Old Course Lower Section Management Project Department I Standard Project

1. Project Overview

1.1. Overview

(1) Section from Nanchang Road to Anlan Road in Qinghe District

This revetment section is 5.34km long and is located on the right bank of the old Yellow River. The pile numbers are 16 289 ~ 21 629; excluding Ninglian Road Yellow River The existing vertical retaining wall revetments, piers, Feiyao Road Bridge, and S327 Provincial Road Bridge on both sides of the bridge are 322m in length, and the total new revetment length is 5.018km.

The protection type of this section is wooden piles combined with plant slope protection. The top elevation of the wooden pile revetment is 8.8m; the pile length is 4.0~11.0m. The diameter of the small head of a wooden pile below 9m shall not be less than 16cm, and the diameter of the small head shall not be less than 22cm if the length is above 9m (inclusive). There is a C20 concrete foundation on the back side of the pile, with a size of 0.4×0.4m, and an imitation wood railing with a height of 1.2m. In order to improve the overall stability of the wooden pile, a flat iron line is installed behind the pile 15cm away from the top of the pile, and the pile body is connected with bolts. To connect, weld open bolts every 30cm to connect to the concrete foundation.

Sections 16 289 to 16 660 and 18 210 to 18 920 adopt wooden piles combined with concrete frames for slope protection. The pile top platform is 5m wide. From the platform to the flood control level 10.60, concrete frame slope protection is used. The slope protection slope ratio is 1:4.0. The top elevation of concrete frame slope protection is 10.60m. The frame grid adopts 2.0m×2.0m square grid and the square grid frame adopts 0.2m ×0.2m concrete grids are arranged in a staggered manner, and bermudagrass turf is laid within the grid. Bermudagrass turf is laid from the flood control level of 10.60m to the top of the embankment, and the top elevation ranges from 10.50 to 15.30m. The net width of the intercepting ditch is 40cm, the net depth is 30cm, and the wall thickness is 12cm. There is a seam every 10m, and a horizontal intercepting ditch is set up every 100m.

Sections 20 050 to 21 629 are protected by wooden piles combined with bermudagrass turf slope protection. The pile top platform is 5m wide, and bermudagrass turf is laid to the top of the embankment. The top elevation ranges from 8.80 to 13.80m; a concrete intercepting ditch is set at the top and bottom of the slope protection. The net width of the intercepting ditch is 40cm, the net depth is 30cm, and the wall thickness is 12cm. The intercepting ditch is divided into slits every 10m, and the transverse intercepting ditch is set up every 100m.

Stake numbers 16 881 to 18 210 and 18 920 to 20 050 are protected by wooden piles. The pile top platform is 5m wide, and a concrete intercepting ditch is set behind the platform. The net width of the intercepting ditch is 40cm, the net depth is 30cm, and the wall thickness is 12cm. There is a seam every 10m, and a horizontal intercepting ditch is set up every 100m.

(2) The eastward section of Anlan Road in the Development Zone

This revetment section is 4.776km long and is located on the right bank of the old Yellow River. The stake numbers are 21 629~25 500 and 26 703~27 608, minus The S237 provincial road bridge and the G2 expressway bridge are 60m in length, and the total length of the new bank protection is 4.716km. Among them, section 25 500 to 26 703 is located in the golf course. The current green environment is good and the bank slope protection has been processed. This section is no longer included in the scope of remediation.

The protection type of this section is wooden piles combined with plant slope protection. The top elevation of the wooden pile revetment is 8.8m; the bottom elevation is determined based on the stability calculation of the wooden piles, and the pile length is 4.0~10.0m. The diameter of the small head of a wooden pile below 9m shall not be less than 16cm, and the diameter of the small head shall not be less than 22cm if the length is above 9m (inclusive). There is a C20 concrete foundation on the back side of the pile, with a size of 0.4×0.4m, and an imitation wood railing with a height of 1.2m. In order to improve the overall stability of the wooden pile, a flat iron line is installed behind the pile 15cm away from the top of the pile, and the pile body is connected with bolts. To connect, weld open bolts every 30cm to connect to the concrete foundation.

The platform at the top of the wooden pile is 3.0m wide, and a water intercepting ditch is set up behind the platform. The net width of the water intercepting ditch is 40cm, the net depth is 30cm, and the wall thickness is 12cm. There is a joint every 10m, and a transverse intercepting ditch is set up every 100m. Together.

The main work content of this construction section is the setting of wooden piles.

1.2. Main project quantities

The total number of wooden piles to be driven in this construction is about 48,762.

1.3. Overview of the surrounding environment

The main surrounding structures are constructed close to the river. The impact of piling on the surrounding environment is generally negligible. However, according to the actual situation on site, the piling process is mainly considered. In view of the construction safety and construction inconvenience, the monitoring of the river bank should be strengthened during the construction process. If abnormal conditions are found, the construction should be stopped and dealt with in a timely manner.

1.4. Composition and characteristics of foundation soil

Based on the field catalog data of drilling holes and indoor geotechnical test results, combined with the engineering geological data of the detailed survey stage and nearby sites, according to the characteristics of the foundation soil Based on the soil characteristics, burial distribution conditions and physical and mechanical properties, the foundation soil within the burial depth range of the site survey can be divided into 5 engineering geological layers according to the soil layers within the drilling depth range. See the following description for details:

Layer 1: plain filling soil (Q4ml). Mainly sandy loam or silt sand. The layer thickness is 0.6~8.3m. Layer 2: sandy loam or silt (Q4al). Slightly dense to medium dense. The layer thickness is 2.2~9.7m. Layer 2-1: Loam (Q4al). Plastic shape. The layer thickness is 3.3m.

Layer 3: Clay (Q4al). Plastic to hard plastic shape. The layer thickness is 1.7~3.4m.

Layer 4: sandy loam or silt, partially loam (Q4al). Medium dense ~ dense. The layer thickness is 0.9~

4.9m.

Layer 5: Clay or loam. It is divided into two sub-layers according to its lithology and strength:

Layer 5-1: Clay interspersed with sandy loam (Q4al). Clay flow molding ~ soft plastic shape. The sandy loam soil is slightly dense to medium dense. The layer thickness is 5.0m.

Layer 5-2: Loam or clay (Q4al). Plastic to hard plastic shape.

2. Construction machinery

Vibrating hammers (commonly known as "robots") are used for piling, which have the characteristics of reasonable structure, large impact capacity, and high work efficiency. When the vibrating hammer is driving piles, the sand layer is vibrated, and the mechanical properties will be significantly reduced, which can effectively reduce pile driving resistance. The vibratory hammer piling is shown in the figure below:

Among them, the pile numbers are 24 385 to 24 741, and the length of the wooden piles is 10 meters. Considering the length of the wooden piles and the geological structure, this section uses a pile driver ship ( Diesel hammer) construction.

3. Construction technology

3.1. Procurement and storage of wooden piles

Wooden piles are mainly purchased through the Northeast Timber Market and transported to the construction site by car; When purchasing, attention should be paid to the wood texture, and the pile length should be slightly larger than the designed pile length. The wood piles used must be of uniform material and must not have excessive bends. When the first and last ends of the wooden piles are connected in a straight line, the deviation between the center of each section and the straight line shall not exceed the relevant regulations; in addition, the pile body shall not have holes, cracks or other defects that are sufficient to impair the strength.

When lifting, loading, unloading, and stacking wooden piles, the pile body must not be subject to impact or vibration to avoid damage to the pile body. When using wooden piles, they should be used in the order in which they are delivered to the construction site, and the wooden piles should be checked to see if they are complete. The foundation for storing wooden piles must be solid and flat, and there must be no subsidence to avoid deformation of the wooden piles.

3.2. Piling process

When piling, each process should be carried out continuously. The process flow is as shown in the figure below:

Piling flow chart

3.3. Piling construction method

3.4.1. Baseline measurement

Before piling construction, review the on-site measurement control baseline and baseline points, and determine the construction plane coordinates according to the site conditions. Preliminary measurement of control points and elevation datum points, and stakeout of the baseline for piling construction.

3.4.2. Site leveling

Level and compact the site on the river bank. According to the actual conditions on site, the roadbed is relatively soft and a gravel cushion should be laid and compacted to ensure pile unloading. For the safety of cranes and construction machinery, road base slabs must be laid on them depending on the situation. The vertical height between the river bank and the water surface should not exceed 1 meter. The pile position should be about 2-5 meters away from the river bank. The width of the temporary road on the river bank should not be less than 3 meters, which can facilitate the construction of machinery and workers.

3.4.3. Timber pile positioning

In order to control the axis position of the wooden pile wall, reduce the plane distortion of the pile and improve the piling efficiency. Process the guide frame with sufficient strength and rigidity.

3.4.4. Piling

In order to make the piles tightly connected, piling is the most critical process. To this end, a vibrating hammer and a walking piling machine are used for one-way sequential construction to achieve the effect of compacting the piles.

The wooden piles are driven by a single pile. A guide frame is set up in front of the sunk wooden pile according to the direction. The guide frame is made of I-shaped steel as a guide for driving the wooden piles. Timber pile driving is mainly based on elevation control.

Strengthen the observation of the piling construction process, keep records of abnormal phenomena during construction, identify the causes of abnormal phenomena, and take corresponding effective measures. When piling is completed, the piles should be clamped in time so that the pile foundation forms a whole, and the pile driving deviation should be measured. During the piling process, the specifications must be strictly followed to control the construction quality of the piling. Choosing sequential operations and relatively convenient operating conditions are conducive to controlling the degree of bonding between wooden piles.

3.5. Quality control of wooden pile driving

During the construction process, we use theodolite to strictly control the verticality and plane position of the wooden piles, and sink the positioning piles to the design elevation as required. To ensure the stability of the positioning pile. After completing the driving of the positioning piles, we drove the next wooden pile one by one to the designed elevation position at one time. The alignment degree of each pile has a great influence on the normal driving of subsequent piles. During the driving process, careful control must be achieved to ensure the quality of pile driving. Specific quality control measures are as follows:

3.5.1. Before driving, ensure that the appearance dimensions, tung oil soaking time, and soaking length of the wooden piles meet the design and specification requirements;

3.5 .2. Axis control

Before pile driving, the axis of the system should be combined. The deviation of the axis of the wooden pile should be controlled within 10cm. Check and adjust the pile clamping device to ensure that the pile axis meets the requirements.

3.5.3. Verticality control

Use theodolite to correct and monitor the verticality of the pile body. The allowable deviation of piling verticality is controlled within 1. From the beginning of pile driving to 2m into the soil, if any deflection is found, the machine should be stopped in time for adjustment. If possible, the pile should be pulled out, cleared and backfilled, and then driven again. When the pile body is seriously tilted, the pile should be pulled out, positioned with steel piles, and then re-sinked.

3.5.4. Elevation control

When the pile tip is located in soft soil, the pile tip reaches the design elevation to meet the requirements, and the allowable deviation of the pile top elevation should be controlled within the range of ±50mm. When the wooden piles are driven close to the specified elevation, the parameters of the vibrating hammer should be adjusted to control the frequency and intensity of vibration to ensure that the pile top elevation meets the design requirements.

3.5.5. Permissible deviations of piling

The permissible deviations of piling are as follows:

The permissible deviation of the axis is 10mm;

The permissible height of the pile tip The deviation is ±50mm;

The allowable deviation of the gap between piles is 50mm.

The allowable deviation of verticality is 1.

4. Construction Guarantee Measures

4.1. Safety Guarantee Measures

Safety construction is a major event related to personal health, family happiness, social stability, and national prosperity. Strengthening the publicity and education of safety knowledge, improving the safety technical quality of construction personnel, strengthening on-site safety management, and strengthening safety precautions constitute several important components of construction safety work.

1. Safety Goal

The safety goal of this project is to be safe and accident-free during the entire project construction period.

2. Safety organizational measures

2.1. Full-time safety officers are fully responsible for safety work during construction, specifically responsible for inspection and supervision, and establishing a safety production assurance system on site.

2.2. Adhere to the pre-construction safety technical briefing meeting system and the pre-construction safety education system

to clarify the safety objectives of the project and implement the safety responsibilities of each position.

2.3. Hold safety work meetings regularly to summarize and arrange safety work.

2.4. Carry out safety activities, arrange safety slogans, banners, etc. on site, and actively carry out safety knowledge publicity and education.

2.5. Safety regulations and operating requirements must be conscientiously implemented. Construction workers must wear safety helmets and illegal operations are strictly prohibited to prevent various accidents.

2.6. Resolutely deal with various safety violations and make rectifications within a time limit.

2.7. Keep daily production safety records and fill in a safety diary.

3. Traffic measures

3.1. When on-site material transport vehicles enter and exit the construction site, dedicated personnel should be arranged at the entrance and exit to direct the vehicles in and out to avoid traffic accidents.

3.2. There should be a relatively large open space at the construction site, especially around the material entrance and exit, to facilitate the turning, U-turn, and entry and exit of material transport vehicles.

3.3. After transport vehicles enter the site, they must first observe the route and move away items that affect traffic. At the same time, pave subgrade steel plates on the soft subgrade road to ensure smooth flow.