Soil-rock composite stratum horseshoe-like shield tunnel design method

Abstract

The invention discloses a soil-rock composite stratum horseshoe-like shield tunnel design method. The method is applied to a soft soil and hard rock composite stratum and comprises the following steps: determining the vertical diameter of the axis of a tunnel cross section according to the use requirements of a shield tunnel; and then designing a horseshoe-like cross section shield tunnel with an upper parabola and a lower elliptic arc according to a soft soil and hard rock composite stratum load mode, so that the theoretical bending moment value of the shield tunnel is zero under the action of the determined load mode. The design method is suitable for engineering and high in pertinence, the adopted load mode can better reflect the actual characteristics of the composite rock-soil body, the shield tunnel bending moment is reduced to the maximum degree theoretically, duct piece reinforcing bars are optimized to the maximum degree, and meanwhile, the opening amount and transverse deformation of the duct piece longitudinal joint connector are reduced, so that the problems of damage and water leakage of the duct piece longitudinal joint connector are solved.

Description

Technical field [0001] The present invention belongs to the technical field of underground space engineering, in particular to a soil - rock formations composite horseshoe design shield tunneling method. Background technique [0002] With the expansion of the scale and scope of the subway construction in my country, rock texture layer subway construction project gradually increased, such as Chongqing, Guangzhou, Qingdao, Dalian and other cities appeared in a large number of rock texture layer is located in the large - span metro station tunnel. Such large span tunnels, is shallow, the upper portion is generally high degree of weathering, broken weak, highly weathered layer of fractured joints, rock down gradually improved, showing the structural features soft hard. Similarly, in the subway tunnel construction process of the PRD, who often encounter Tunnel in the Ministry of soft soil, the lower part of hard rock of "soft down hard on the" complex formation. Another example is the...

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Problems solved by technology

Those skilled in the art suggest that when the segment is divided into blocks, the joint position should be set at the position where the bending moment of the segment is the smallest. Of course, the theoretical best position is the zero bending moment, but it is ideal and the construction is very difficult.

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