Retaining structure of cement-soil pile-wall for rail beam and construction method

Abstract

The invention provides a support structure for a rail beam cement-soil pile-wall to form an underground continuous wall for the support of foundation pits and side slopes. The support structure is composed of rail beam cement-soil pile support components in a continuously occluded arrangement form and support components in the foundation pits or pit wall anchor components. The rail beam is composed of a rail, a rail supporting component for supporting rails between rails, a connection flange in beam end bolts, a heat circulating reflux component attached to the inside of the beam and release agent paint to rail beam surfaces. The pile wall support components have the advantages of large buckling strength and stiffness, small wall deformation, flexible soil-cement pile material ratio, even mixing, convenient, flexible and fast construction, easy recovery of rail beams, low cost, no pollution, etc. The invention can be widely used in foundation pit and side slop support and protection works.

Description

technical field [0001] The invention relates to the field of pile wall support for foundation pits and side slopes in civil engineering. Background technique [0002] In the existing known technology, the SMW construction method (that is, the H-shaped steel cement-soil pile wall support structure) has been widely used in civil engineering at home and abroad. This kind of support structure realizes the support function of the foundation pit slope and other slopes in this way, that is, a special drilling mixer equipped with a stirring mechanism is used to drill holes in the formation, and the tip of the drill pipe is used to The cement slurry is injected, mixed with the in-situ soil in the formation forcibly, and a series of cement-soil row piles are formed in situ. Before the cement-soil row piles are solidified, H-shaped steel is inserted, and after solidification, a load-bearing and It is a composite structure of underground diaphragm wall with pile column type that can pr...

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Problems solved by technology

[0003] To a certain extent, the SMW construction method can recycle the H-shaped steel in the construction method and save engineering investment. However, it is restricted by the soil conditions of the site, the mixing method, and the bending stiffness and strength of the H-shaped steel itself. The depth of pit support is often limited. According to the existing domestic construction performance, the depth of foundation pit support is generally not more than 13m. The diameter of the large mixing pile increases the construction cost and difficulty, and the construction quality of the mixed soil often becomes uncontrollable when the construction diameter of the too large mixing pile is too large, and compared with other traditional support methods, it also loses its unique economy. and technical advantages, so this technology is generally not suitable for foundation pits with excessive excavation depth

Another defect of this technology is that although the use of ointment-like release agent has a better effect of pulling out steel in cohesive soil strata, if it is in coarse-grained sandy soil stratum, even if a thicker stripping agent is applied to the surface of the steel In the case of mold agent, the release agent on the surface will also be lost due to friction with the surrounding cement soil during the insertion process, resulting in increased pull-out resistance and difficulty in removal; another is that the construction method has relatively high requirements for the construction site High, when the special section steel is pulled out and recovered, if the site around the foundation pit is narrow and there is no site and space that can accommodate a truck crane over 15 tons, then even if the section steel is pulled out by the cylinder jack, it cannot be hoisted away in its entirety, but only It can take segmental lifting and segmental cutting (the segmental length depends on the lifting capacity of the tower crane, generally not exceeding 3.5m), and the operation measures of tower crane lifting, the loss of section steel is very large, and it is troublesome to remove the support in the pit , taking up a long construction period, greatly reducing the original economic benefits

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