Transition line section tunnel CRD (Cross Diaphragm) construction method

Abstract

The invention discloses a transition line section tunnel CRD (Cross Diaphragm) construction method. The tunnel face outside the range of core soil of upper bench is closed by C20 concrete (50mm in thickness), before the grouting of the advanced small pipes in each row. A locking anchor pipe is arranged at a steel frame joint, and the anchor pipe is a steel perforated pipe shown in the description,where L is 2.0m. The front-back staggered space between pilot tunnels is not less than 10m, and the specific staggered length is adjusted appropriately according to the cross section length. Residuesbelow the foundation must be cleared before mounting the steel frame, the overexcavation part is filled properly by sprayed concrete, then the steel frame is located on the sprayed concrete cushion layer, so as to prevent overall sinking of the steel frame or sinking of the two non-uniform sides. the running tunnel excavation footage is equal to the grille space; a civil defense section, a transition line section 1, a transition line section 2 and a transition line section 3 are subjected to CRD construction; each pilot tunnel is built by the benching tunneling method; the construction is carried out under the principles of advanced pipe, strict grouting, short footage, strong support, early closing and frequent measurement', thereby guaranteeing safe and smooth tunnel construction.

Description

technical field [0001] The invention relates to the technical field of subway tunnel construction, in particular to a CRD method construction method for a crossing section tunnel. Background technique [0002] In the construction of subway tunnels, the cross-section tunnel needs to be excavated with a large section using the mining method to meet the requirement that the main line section and the parking line are in the same large-section tunnel. The large-section excavation generally adopts the middle partition wall method (CD method) or Cross partition wall method (CRD method), CD method is a construction method in which one side of the tunnel is excavated in sections first, and the partition wall is constructed, and then the other side is excavated in sections in a long-span tunnel with weak surrounding rock. The CRD method is a construction method in which in a long-span tunnel with weak surrounding rock, one side of the tunnel is excavated in sections, and the middle pa...

AI Technical Summary

Problems solved by technology

When the span of the section is too large, because the CD method and the CRD method are used for construction, the span is divided into two excavations, and there is a problem that the section span of each excavation is too large. During the excavation construction process , prone to tunnel roof collapse

In addition, after the excavation of the tunnel section is completed, the initial support needs to be done first, including the support of the middle partition. When the secondary lining is applied, the middle partition of the initial support must be removed. It is easy to cause the top of the tunnel to collapse and cause construction safety accidents

Images