Retaining wall refers to the structure that supports subgrade fill or hillside soil to prevent deformation and instability of fill or soil. On the cross section of the retaining wall, the part that directly contacts with the supported soil is called the back of the wall; The part opposite to the back of the wall and facing the air is called the wall; The part in direct contact with the foundation is called the basement; The top surface of the wall opposite to the basement is called the top of the wall; The front end of the basement is called the wall root; The rear end of the base is called the heel. Among them, how should the construction scheme of retaining wall be formulated? Here is a detailed introduction of the retaining wall construction scheme brought by the construction network for reference.

Retaining wall construction scheme

1. survey and setting out: set out the edge of retaining wall with total station, draw out the excavation scope, nail the pile position, and arrange control piles near the construction site.

2. Foundation pit cleaning and basement treatment: excavation shall be carried out according to the measured foundation pit construction scope and design depth. Wall foundation should be placed on reliable rock stratum, and the foundation should be buried in 1 ~ 2m strongly weathered bedrock stratum. If the foundation does not conform to the design, it should be reported to the supervision engineer to change the construction plan.

3, template installation

A, template production: steel template should be standardized combination template. The assembly of composite steel formwork shall conform to the current national codes and standards. All kinds of bolted connections shall conform to relevant standards. Steel formwork and its accessories shall be processed according to the standard processing drawing, and the finished products can be used only after passing the inspection.

B, template installation: template and steel bar installation work should be coordinated, prevent steel binding template should be installed after the completion of steel bar installation. When installing the side formwork, the formwork should be prevented from shifting and deforming. The foundation side formwork can be supported and fixed outside the formwork. Whether the tie rod poured in concrete is pulled out or not, corresponding measures should be taken. For small structures, metal wires can be used instead of pull rods. After the formwork is installed, check its plane position, top elevation, node connection and vertical and horizontal stability, and concrete can be poured only after it is qualified. When pouring concrete, if it is found that the template may exceed the allowable deviation deformation value, it should be corrected in time. Template in the installation process, must set up anti-overturning facilities.

4, concrete production and transportation

A, concrete mixing: when mixing concrete ingredients, all kinds of weighing instruments should be kept accurate. The moisture content of aggregate should be detected frequently, and the detection times should be increased in rainy season construction, so as to adjust the aggregate and water quantity accordingly. The concrete mixture shall be evenly mixed and the color shall be consistent, and segregation and bleeding shall not occur when transported to the site. The concrete is transported by tank car, which makes the pouring work uninterrupted. And make the concrete transported to the pouring site still maintain uniformity and specified slump. After the concrete is transported to the pouring site due to the long distance, it should be stirred again in the tank car for 1 ~ 2 minutes before the concrete construction. It is forbidden to use unqualified concrete for construction.

B, concrete pouring:

Before pouring concrete, the supports, templates, steel bars, etc. shall be inspected and recorded, and concrete shall be poured only after meeting the design and construction requirements. Before pouring concrete, the sundries and accumulated water in the formwork should be cleaned. Template if there is a gap, the application of sponge or double-sided adhesive tape, template coated with release agent (oil such as waste engine oil shall not be used).

When pouring concrete, use an internal vibrator to vibrate, and no vibration leakage or excessive vibration is allowed. Concrete should be poured in layers according to a certain thickness, sequence and direction, and the upper concrete should be poured before the lower concrete is initially set or can be reshaped. The thickness of layered concrete pouring shall not exceed 30㎝. After the first layer of concrete construction is completed, rubble will be poured manually, and the next layer of concrete construction will be carried out after the pouring is completed according to the specification requirements. When concrete is directly dumped from a height, its free dumping height should not exceed 2m to avoid segregation. When the falling height exceeds 2m, it shall fall through facilities such as string barrel, sliding barrel or vibrating sliding barrel. When the falling height exceeds 10m, a deceleration device shall be set (multidirectional baffles shall be set at different heights of the string drum). The pile height of concrete under the bucket shall not exceed1m.

Pouring shall be carried out continuously. If it is necessary to stop for some reason, the stopping time should be less than the initial setting time or the remolding time of the previous layer of concrete. The position of construction joints should be determined before concrete pouring, and should be retained in the parts of the structure where the shear force and bending moment are small and convenient for construction. After concrete pouring is completed, the exposed surface of concrete shall be repaired in time. After the initial setting, it should be applied for the second time, and calendered or painted. When the exposed area is large or the weather is bad, it should be protected by felt, but before curing, the covering must not touch the concrete surface.

Debris, dust, etc. The flaky on the surface should be removed before mixing. Generally, the content of flaky does not exceed 25% of the total volume of masonry, and the construction is controlled at 20%. When mixing, stones shall not be thrown at will, and the clear distance shall not be less than 100mm, and the clear distance from the side and top surface of the structure shall not be less than150 mm. Stones shall not touch embedded parts or directly touch the basement and formwork.

5, concrete curing and template removal

After pouring is completed, cover with water as soon as possible after initial setting. Covering shall not damage or pollute the concrete surface. When concrete is covered with formwork, the formwork should always be moist during curing. The curing standard is to keep the concrete surface moist frequently, and the curing days shall not be less than 7 days. Dismantling: Dismantling shall be carried out in the order required by the design. If there is no requirement in the design, the order of first supporting and then dismantling shall be followed, and it is forbidden to discard it when dismantling. The unloading of supports and arches shall be carried out according to the proposed unloading procedure and shall be completed within several cycles. The unloading amount should be small at first, and then gradually increase. Unloading should be balanced in the vertical direction and unloaded simultaneously in the horizontal direction. Dismantling templates, brackets and arches are not allowed to be carried out by slamming or twisting. After the formwork and support are dismantled, they should be maintained and sorted out and properly stored.

6. Settlement joint setting

Settlement joints should be set according to the design position. When the retaining wall is constructed, it should be constructed in sections according to the position of settlement joints, and the retaining wall is completed. The settlement joint should be filled with asphalt wadding along the inside, outside and top with a depth of 10 ~ 20 cm.

For more information about bid writing and improving the winning rate, click on the bottom customer service for free consultation.