Tunnel fabricated prestressed lining design method

Abstract

The invention discloses a tunnel fabricated prestressed lining design method. The method comprises the steps of survey and calculating design and preparation and installation of sectional type liningsegments. The survey and calculating design comprises the following steps of A, determining an inner limit of a tunnel and an inner contour line of a lining; B, setting lining and inverted arch thickness values; C, calculating the pressure of surrounding rocks in the tunnel; D, calculating lining internal force and all loads borne by the surrounding rocks; E, calculating stress; F, conducting prestressed reinforcement arrangement; and G, conducting checking calculation. During preparation and installation of the sectional type lining segments, a factory manufactures a plurality of segments ina fragmentation mode and installs prestressed tendons; and the plurality of sectional type lining segments are spliced on site. According to the method, structural design is performed through a load-structure method to obtain design data, the segments can be put into use after being prefabricated in the factory and installed on site, the construction progress is improved, the finished prestressedsteel bars of a finished product are arranged on the tensioned side, the negative bending effect generated when the prestressed steel bars are arranged on the same side is overcome, the joint connection is tight, the water seepage and gushing probability is reduced, and the quality is ensured.

Description

technical field [0001] The invention relates to the field of tunnel engineering construction methods, in particular to a design method for a tunnel assembled prestressed lining. Background technique [0002] In the current construction of transportation infrastructure such as subways, highways, and railways, a large number of tunnel projects will be encountered. In order to ensure the safety of tunnel construction and operation, the secondary lining of the tunnel is one of the main support methods at this stage, and the formwork is often used for cast-in-place construction. However, considering the construction quality and project progress, this method has the following shortcomings. [0003] First: At present, the tunnel lining structure is divided into primary support and secondary lining. The primary support is the support composed of shotcrete, bolts, steel mesh, steel arches, etc., and the secondary lining is used inside the primary support. Formwork cast-in-place meth...

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Problems solved by technology

[0006] In order to overcome the limitations of the construction method of the formwork cast-in-place lining in the existing project, which will lead to slow construction progress, the shortcomings of lining damage and water leakage after pouring, and the lack of consideration of the crack resistance of the lining in the design, the prestressed reinforcement is the same Curvature arrangement will affect the quality of the lining. The present invention provides the load-structure system as the basic design, and manufactures the finished tunnel lining segments in the factory in sections (multiple lining segments are spliced ​​laterally in the tunnel to form arch-shaped one-stage lining, and several sections of lining are combined longitudinally in the tunnel to form the overall lining in the tunnel), which can be put into use quickly after subsequent on-site installation, which improves the construction progress; and in the finished product, according to the corresponding segment According to the actual bending moment distribution of the finished lining, the prestressed reinforcement is arranged on the tension side of each lining segment, which effectively overcomes the negative bending moment when the prestressed reinforcement is arranged on the same side of the lining in the existing design and construction. A tunnel assembly prestressed lining design method that makes the joints more tightly connected, reduces the chance of water seepage and water gushing, and ensures the overall quality of the tunnel lining

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