Construction method for excavating water-rich shallow underground excavation tunnel

Abstract

The invention discloses a construction method for excavating a water-rich shallow underground excavation tunnel. The construction method includes the following steps that first, phi-42 advanced small pipes are constructed within the range of 180 degrees of the arch of the tunnel and the range of the top heading side wall through a steel frame erected in the last cycle, and advanced grouting supporting is performed; a first part is excavated; a preliminary support and a temporary support on the periphery of a heading of the first part are constructed, 4 cm thick concrete is sprayed preliminarily, a reinforcing mesh is installed, a steel frame and a temporary steel frame A are erected along with fluctuation of the rock face, and locking tremies are arranged; after holes are drilled and system anchor rods are arranged, concrete is sprayed again; second, a second part is excavated; 4 cm thick concrete is sprayed preliminarily on part of the periphery of the heading, and a reinforcing mesh is arranged; a steel frame on the periphery of a hole is lengthened through connection; after holes are drilled and system anchor rods are arranged, concrete is sprayed again; third, a third part is excavated in a blasting mode; fourth, a fourth part is excavated in a blasting mode. According to the construction method, the workloads for partition wall construction and removal are saved in construction, the tunnel construction progress is accelerated, the machine utilization rate is increased, energy waste is reduced, the construction period is short, and cost is low.

Description

technical field [0001] The invention relates to a tunnel excavation construction method. Background technique [0002] In the construction of shallow buried tunnels, the excavation methods commonly used include the full-section method, the step method, the CD method, and the CRD method. The selection of tunnel excavation methods is mainly based on geological conditions. For example, the full-section method and the step method are suitable for surrounding rocks with good strata. The CD or CRD method is often used in the construction of urban underground projects with strict requirements. However, various special geological conditions are often encountered in tunnel excavation. It is difficult to find a standard excavation method for special geological sections, especially in the construction of subway underground tunnels. In the construction of the tunnel, it is often encountered that the upper section of the tunnel is soft and the lower section is hard, that is, the upper s...

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Problems solved by technology

[0003] 1. Using the full-section method or step method is unfavorable to the control of settlement, horizontal convergence and road settlement in the cave, and cannot ensure the safety of construction in the cave and road driving;

[0004] 2. Using CD or CRD construction method, there are many procedures and high cost, and the lower section needs to be blasted. The blasting vibration will have an adverse effect on the middle partition or temporary inverted arch, thus affecting the safety of tunnel construction

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