A construction method for silt soil layer shield cutting piles to cross the river

Abstract

The invention relates to a construction method for crossing rivers with shield tunneling piles in powder soil stratum, including: material preparation; specific measures for pile foundation cutting by shield tunneling: pile cutting construction control, monitoring control, construction control for crossing rivers, and construction of unknown obstacles Measures, pipeline protection measures; shield propulsion parameter setting; construction measures for crossing the river; control technology after the shield passes through the pile foundation; monitoring frequency control; inspection control in the cave. The beneficial effects of the present invention are: the method is simple in steps, reasonable in design, simple and convenient in construction, low in investment cost, and strong in practical engineering operations; the method of the present invention can improve the efficiency of tunneling under the tunnel, and control the attitude of the shield machine, thereby It reduces the possibility of accidents in the tunnel and lays a favorable foundation for the subsequent successful crossing; it has high practical value and good use effect. Compared with the existing tunnel construction method of underpassing, it shortens the construction period and greatly reduces the construction cost.

Description

technical field [0001] The invention belongs to the technical field of cutting existing pile foundations by shield tunneling, and in particular relates to a construction method for cutting piles by shield tunneling and crossing rivers in silty soil strata. Background technique [0002] In recent years, with the large-scale construction of urban subways and related municipal projects, shield tunnels have been used more and more in China. In the stage of shield tunneling, it is often encountered that existing building pile foundations need to be removed by construction methods such as pile extraction, so that the shield tunnel can pass normally, but this kind of construction method has a long construction period, high construction cost, and requirements Higher, often can not achieve the expected construction effect. [0003] There are many risks in adopting common pile cutting construction method. For example, if the excavation speed of the shield machine is too fast during ...

AI Technical Summary

Problems solved by technology

It is difficult to control the attitude during the excavation process. If the shield machine moves forward in a serpentine manner, the risk of the shield machine getting stuck will also increase; the shield machine may also be seriously damaged, which will affect the subsequent construction

Excavated pile tips and broken pile heads may advance together with the shield machine to cause over-excavation in the ground, affecting the control of ground subsidence and the safety of subsequent houses and pipelines; in addition, the shield screw conveyor may be stuck by steel bars, Shield machine does not work properly

After the shield machine cuts the pile foundation, the steel bars in the pile foundation will enter the screw conveyor, and the steel bars may be stuck in the gap between the screw blade and the inner wall of the screw machine sleeve, causing the screw machine to be stuck and affecting the later excavation; The post piles will act on the tunnel segments with point loads and transfer the loads directly to the tunnel lining. During the operation of the subway, the interaction between the tunnel and the bridge will bring hidden dangers to the safe use of both; when the shield machine crosses the river When the overburden is shallow and the stability of the soil is poor, it is easy to cause perforation at the bottom of the river and backflow of river water.

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