What Is a Cantilever Wall?

The cantilever retaining wall is composed of a base plate and a straight wall fixed on the base plate, and the stable retaining wall is mainly maintained by the weight of the fill on the base plate. It is mainly composed of three reinforced concrete members such as a standing wall, a toe plate and a concrete plate.

The cantilever retaining wall is composed of a wall body, a toe plate and a lintel plate. Due to its strong bending resistance and good stability, it can be used on the slope of a soil with a high retaining height. Its structural requirements as follows:

1. Wall

Generally, the inner side of a cantilever retaining wall is made into a vertical surface, and the wall surface can be made into a slope of 1: 0.02 to 1: 0.05. The specific slope should be determined according to the height of the retaining wall. When the height of the retaining wall is small, the wall The body can be made of equal thickness; when the height is larger, the slope of the wall is larger, and the minimum thickness of the wall top is 200 mm.

2. Floor

The bottom plate is composed of a toe and a wall panel. The bottom plate is generally set horizontally to make a variable thickness plate, and the bottom plate is horizontal. The bottom of the wall panel is horizontal and the top surface is inclined. The length is determined by anti-slip stability check. The root thickness is generally 1/12 1/10 of the wall panel length and should not be less than 200 mm. The length of the wall panel is determined by the resistance. Overturning safety factor,

A cantilever retaining wall is a lightweight supporting structure. The anti-sliding and anti-overturning of its supporting structure mainly depends on the weight of the wall body and the gravity effect of the filling soil (including load) above the wall floor. In addition, if a tenon is installed on the wall floor, the sliding stability of the retaining wall will be greatly improved. Sex. Because the retaining wall uses a reinforced concrete structure, the thickness of the structure is reduced, the weight is reduced, and the rigidity of the reinforced concrete floor is increased, which makes the height of the retaining wall of the retaining wall higher and improves the adaptability under the condition of low bearing capacity of the foundation. Therefore, the advantages of the cantilever retaining wall are mainly reflected in the small structure size and light weight, which is convenient to use in the fill section where the stone is lacking and the bearing capacity of the foundation is low. ^[2]

The design calculation of cantilever retaining wall mainly includes: calculation of lateral pressure, determination of wall section size, design of reinforced concrete structure, check of crack width and check of stability, etc.

Generally, the cross-section dimensions of the wall are determined by a trial algorithm, that is, the trial calculated dimensions of the section are first calculated, the side pressure acting on it is calculated, and the lengths of the wall panel and the toe panel are finally determined through all the stability checks.

The design of the reinforced concrete structure is mainly based on the calculation of the internal force and the reinforcement of the wall section dimensions that have been initially prepared. In the reinforcement design, the section size may be adjusted, especially the thickness of the wall. Under normal circumstances, the adjustment of the wall thickness has little effect on the overall stability, and the stability check of the entire wall can no longer be performed.

The stability check mainly includes anti-sliding, anti-overturning, foundation stability check and so on. The calculation of the maximum crack width shall meet the requirements of relevant codes. In addition, the cantilever retaining wall is considered according to the problem of plane strain, that is, one meter is taken along the length of the wall for design calculation. ^[3]

The design of a cantilever retaining wall consists of four steps.

According to the needs of the supporting environment, the wall height and the corresponding wall structure size are drawn up. Generally, an extension meter is taken in the direction of the wall extension.

Determine the structural load (wall weight, earth pressure, soil filling gravity) according to the proposed wall structure size, and then perform the sliding and anti-overturning stability check of the wall to confirm whether a tenon is needed .

Check the bearing capacity of the base plate to confirm whether the size of the base plate meets the requirements.

Wall structure design and crack width check calculation. ^[2]