Composite retaining structure of variable stratum non-equal-size double-circular-arc foundation pit

Abstract

The invention relates to the technical field of engineering construction, specifically to a composite retaining structure of a variable stratum non-equal-size double-circular-arc foundation pit. A double-circular-arc retaining mechanism is arranged in a non-equal-size double-circular-arc section foundation pit; the double-circular-arc retaining mechanism comprises a double-circular-arc continuouswall and more than three layers of annular supporting mechanisms; the three layers of the annular supporting mechanisms are connected by using an internal ring connecting beam and one pair of perpendicular straight supporting beam mechanisms so that a stress transmission passage is formed between the internal ring connecting beam and an external circular supporting beam; on the one hand, a reasonable distribution effect on the stress of the side wall of the double-circular-arc section foundation pit is realized; and on the other hand, the deformation of the annular supporting mechanisms can also be controlled; and as the annular supporting mechanisms are connected with each other through upright mechanisms in the axial direction in a through manner, the integral intensity of the double-circular-arc retaining mechanism is enhanced.

Description

technical field [0001] The invention relates to the technical field of engineering construction, in particular to a combined support structure for non-equal-diameter double-arc foundation pits in variable strata. Background technique [0002] With the rapid development of urbanization, urban land resources have become more and more tense. Due to the constraints of existing building facilities and traffic arteries, new foundation pits often appear in irregular forms, that is, special-shaped foundation pits. Especially in the excavation of subway foundation pits in urban areas with dense buildings, the foundation pit support structure must not only ensure the safety and stability of the foundation pit itself, but also consider the impact of the excavation process on adjacent buildings. [0003] At present, the commonly used forms of subway foundation pit support mainly include anchor rods, underground diaphragm walls, row pile support, etc. Although the underground diaphragm ...

AI Technical Summary

Problems solved by technology

Although the underground diaphragm wall has high strength and strong bearing capacity, it is expensive and increases the cost; row pile support has a good water-stop effect, but it is not suitable for soft soil foundations and deep foundation pits; although the cost of bolt support is lower than that of underground Diaphragm wall and row of piles, however, there is a gap between the support of underground diaphragm wall and row of piles in terms of strength and water-stop effect

[0004] For the excavation process of the subway foundation pit, there is a variable stratum in which the rock mass invades the soil. Due to the large difference in physical parameters between the rock mass and the soil mass, the force of the special-shaped foundation pit in the variable stratum is more complicated, and the support structure of the foundation pit It is more difficult to control the force and deformation, and the force transmission effect of the conventional support form is not obvious, especially in the deep and large special-shaped foundation pit under the variable stratum, it is difficult for a single support form to meet the support and cost requirements of the foundation pit at the same time

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