Drainage system of cut-type open cut tunnel

Abstract

The invention relates to a drainage system of a cut-type open cut tunnel. An upper water collecting channel and a lower water collecting channel are arranged in a backfill layer of the open cut tunnel, each water collecting channel comprises a longitudinal drainage pipe and a fixing base used for fixing the longitudinal drainage pipe, a plurality of transverse water guide pipes are arranged between the two longitudinal water drainage pipes at intervals, and a plurality of water inflow holes are annularly formed in the upper portions of the longitudinal drainage pipes; a drainage filtering layer is further arranged between a backfill soil and stone layer and a side wall backfill layer; two rows of upward inclined drainage holes are further formed in a side slope in the longitudinal direction of the tunnel at intervals; a transverse drainage slope is arranged on the top face of the side wall backfill layer. According to the drainage system, on the basis of a traditional drainage system of the open cut tunnel, the drainage mode that a drainage device is tightly attached to an open cut tunnel lining is changed; by arranging the water collecting channels, the longitudinal drainage pipes, a concrete pedestal, the upward oblique drainage holes, the drainage filtering layer, the transverse drainage slope and the like, the effect of drainage at the back of the lining is greatly improved, and the defects of drainage at the back of a current mountain tunnel open cut tunnel lining are overcome systematically.

Description

technical field [0001] The invention relates to the technical field of design and construction of open tunnels for roads, railways and municipal mountain tunnels, and in particular to a drainage system of a cutting-type open tunnel structure. Background technique [0002] The open tunnel is a tunnel in which a lining structure is built in a road cutting or a half road cutting by the open cut method, and earth and rocks are backfilled on its surface. Open tunnels are mainly used for tunnel entrances or cutting sections that suffer from landslides, falling rocks, flowing rocks, and flowing mud. They are commonly used structures in the design and construction of highways, railways, and municipal mountain tunnels. [0003] At present, the drainage behind the lining of the open tunnel in mountain tunnels is often arranged by vertical and longitudinal perforated drainage pipes close to the outer edge of the open tunnel structure, and then set up horizontal drainage pipes to guide ...

AI Technical Summary

Problems solved by technology

[0003] At present, the drainage behind the lining of the open tunnel in mountain tunnels is often arranged by vertical and longitudinal perforated drainage pipes close to the outer edge of the open tunnel structure, and then set up horizontal drainage pipes to guide the drainage to the ditch inside the tunnel. However, the lining is often damaged due to poor construction. Sinking water at the back may even cause the loss of backfill soil in the open hole and form a cavity, which is unfavorable to the stress of the open hole lining structure

The main disadvantages of this drainage method are:

[0004] (1) The vertical drainage pipe is buried in the backfill, and the backfill construction is often rough, and the drainage pipe is easily damaged or congested;

[0005] (2) The longitudinal drainage pipes are easily squeezed during construction, resulting in bending and deformation of the drainage pipes and poor drainage;

[0006] (3) Open cut slopes often have loose soil layers and broken rock mass, and surface rainwater seeps down and collects behind the lining along the slope. If the drainage is not smooth, it will affect the stability of the slope and cause changes in the stress of the open tunnel structure. It may cause the structure of the open hole to bear the water pressure, which will lead to cracking of the open hole structure, water leakage and other diseases after a long period of time

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