Shield construction method for shallow buried section under lake

Abstract

The invention relates to a shield construction method for a shallow buried section under a lake, and belongs to the field of shield tunnel construction, the method comprises the following steps of: after determining the position of a cofferdam to be constructed above the shallow buried section under the lake, putting a sand bag into the lake in a mode of sliding along a slope from the shore to theinside of the lake, and folding to form the cofferdam; draining the lake water in the folded cofferdam and laying a sand bag cushion layer on the bottom of the lake water; then carrying out stirringpile reinforcement on the soft stratum below the sand bag cushion layer; removing the sand bag cushion layer and digging out the surface soil layer above the soft stratum after the implementation of the stirring pile reinforcement; then throwing thick stones or block stones into the cofferdam and vibrating and pressing while the stones are filled, and using the cofferdam as a grouting platform; and then grouting and reinforcing the soft stratum, wherein, after the grouting and reinforcing strength reaches the requirement, the shield passes through the shallow buried section at the bottom of the lake, and after the shield passes through the lake, the sand bag cofferdam is removed, and the remains in the lake are removed. According to the invention, the soft stratum of the shallow buried section under the lake is reinforced and filled in time, so that excessive lake bottom settlement is avoided, and accidents such as burst or large-area collapse and the like are prevented from affectingengineering safety and environmental safety.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction and is suitable for underground engineering construction, in particular to a shield tunnel construction method for a shallow buried section under a lake. Background technique [0002] With the rapid development of the national economy, some developed areas in my country have entered the era of large-scale development and utilization of underground space, and the construction of subways will be the focus of urban underground space development in the 21st century in my country. There must be intervals in the construction of urban subway networks The engineering problem of mutual crossing of tunnels, that is, the long-distance construction of the shield machine through the lake, the sand layer of the excavation section is widely distributed, and the buried depth of the tunnel at the bottom of the lake is relatively shallow. Affected by factors such as subsidence or uplift sensitivity...

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Problems solved by technology

[0002] With the rapid development of the national economy, some developed regions in my country have entered the era of large-scale development and utilization of underground space, and the construction of subways will be the focus of urban underground space development in the 21st century in my country. There must be intervals in the construction of urban subway networks The engineering problem of mutual crossing of tunnels, that is, the long-distance construction of the shield machine through the lake, the sand layer of the excavation section is widely distributed, and the buried depth of the tunnel at the bottom of the lake is relatively shallow. Affected by factors such as settlement or uplift sensitivity, there is a greater risk in shield construction. and long duration

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