Six-pilot-tunnel twelve-step underground space excavation support and protection method

Abstract

The invention discloses a six-pilot-tunnel twelve-step underground space excavation support and protection method and belongs to the field of construction engineering. According to the method, outer contour line straight walls are excavated first along a structure and a phi108 advanced large pipe shed is arranged at a flat top position, and the outer contour line straight walls and the phi108 advanced large pipe shed are used as an integral support of an underground space after grouting; according to the size of the structure, an excavation section is divided into six pilot tunnels, and each pilot tunnel is divided into upper and lower steps and excavated in two steps, so that there are six pilot tunnels excavated in twelve steps in total; every two adjacent pilot tunnels are excavated ina jumped manner and staggered in the front and rear direction, the first, third and fifth pilot tunnels are first constructed, and then the second, fourth and sixth pilot tunnels are constructed. In this way, the large section is integrally broken into parts, the exposed area of a tunnel face is reduced, and the second, fourth and sixth pilot tunnels are constructed later, for example, three pieces of core soil stabilize ground loads. After the first, third and fifth pilot tunnels are closed into loops and the settlement is stable, the second, fourth and sixth pilot tunnels are excavated, so that the relative settlement is less, and the excavation is faster. The method has good safety and high efficiency.

Description

technical field [0001] The invention relates to the field of construction engineering, in particular to a six-pilot twelve-step underground space excavation and support method. Background technique [0002] In the current process of urbanization, the land in the core built-up area is particularly scarce, and the development of underground space is becoming more and more urgent. In the built-up area, the ground pipelines are generally dense, the traffic flow is relatively large, and there are many surrounding buildings and structures. The construction space that can be provided is small and the method of large excavation cannot be adopted. Moreover, the excavation section is irregular, and it is not easy to adopt standardized mechanical operations. The development of underground spaces such as street crossing passages, underground parking lots, and underground civil air defense shopping malls should improve investment efficiency. The burial should not be too deep, and the de...

AI Technical Summary

Problems solved by technology

[0004] However, the existing methods of preventing land subsidence and the secondary disasters it brings have poor safety and low construction efficiency

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