Construction method for deformation control via horizontal whirling jet grouting of long cantilever in soft-rock tunnel

Abstract

The invention discloses a construction method for deformation control via the horizontal whirling jet grouting of a long cantilever in a soft-rock tunnel. The method comprises the following steps of: (1) drilling on the periphery of a dug outline, carrying out the whirling jet grouting while retreating a drill stem, and lowering a first profile component after the whirling jet grouting to form a first profile pile body; (2) repeating the step (1) to construct a first curtain system; (3) drilling on a tunnel face designed in a tunnel, carrying out the whirling jet grouting while retreating the drill stem, lowering a second profile component after the whirling jet grouting to form a second profile pile body; (4) repeating the step (3) to construct a second core earth reinforcing system; (5) carrying out the mechanical digging and initial supporting on a large section; (6) drilling in the arch springing position of middle and lower steps obliquely towards the lower direction of the tunnel at 30-45 degrees, lowering a third profile component to form a third profile pile body; and (7) repeating the step (6) to construct a locking whirling jet grouting pile stabilization system. According to the construction method, the advanced reinforcement of a horizontal whirling jet grouting pile with a highly strong tunnel outline, the binding and deforming effect of a tunnel face glass fiber anchor stem, and the anchoring of the locking whirling jet grouting pile are utilized, and the deformation of rock-soil is effectively controlled.

Description

technical field [0001] The invention relates to a tunnel and underground engineering construction method, in particular to a tunnel and underground engineering weak surrounding rock pre-reinforcement and excavation construction method. Background technique [0002] In the construction of tunnels and underground projects in weak and broken ground, safety problems such as large deformation of surrounding rocks and collapse of working faces are prone to occur, as well as technical problems such as slow construction progress and extremely low work efficiency. In order to ensure the construction safety of tunnels and underground works, the following three construction methods for soft rock tunnels are currently used in the industry. [0003] One is the multi-step CRD method. Although this method reduces construction risks to a certain extent, it has many temporary supports, consumes materials, complicated procedures and slow progress. In the construction of weak surrounding rock...

AI Technical Summary

Problems solved by technology

The advanced support construction technology of this patent application has the following shortcomings or deficiencies: (1), the process sequence is drilling, washing, withdrawing the drill pipe, installing pipe sheds, installing grouting pipelines, and grouting, wherein the grout is in the pipe shed The proximal end of the pipe shed is injected, flows out from the far end of the pipe shed, and flows back along the drilled hole. Therefore, washing the hole is an essential step, because according to this process, the pipe shed cannot be installed smoothly without washing the hole, but washing The hole step will increase the cost and man-hours; (2) In addition, since the grout is injected from the proximal end of the pipe shed, flows out from the far end of the pipe shed and flows back along the drill hole, it can only be judged whether to inject grout by monitoring the pressure It is successful, but it is difficult to ensure that there are no interruptions or weak areas in the middle, which may lead to problems such as broken piles, non-occlusion, pile diameter reduction, etc., and it is difficult to meet the requirements of excavation construction; (3) In addition, flanges need to be arranged at the proximal end of the construction Sealing devices such as hole sealers and rubber pads are used to ensure the pressure of grouting, which will increase man-hours and costs, and there will also be situations of grout running and leaking; (4), because the core soil is not pre-reinforced, During the excavation of the tunnel, it is easy to produce extrusion deformation of the tunnel face, pre-convergence of the tunnel body, and large convergence deformation

According to the process of this patent application, the drill pipe and the drill bit are left in the borehole as a tube shed to form an integral body with the pile body after one-time use, resulting in a waste of resources. The process of grouting from the pipe shed and the core soil is not reinforced, so it also has the above-mentioned shortcomings (2), (3), (4) of the Chinese patent application No. 200910227790.6

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