Design method of extruded surrounding rock tunnel structure

Abstract

The invention discloses a design method of an extruded surrounding rock tunnel structure. The design method comprises the following steps: determining key influence factors for designing the extrudedsurrounding rock tunnel structure as a surrounding rock strength-stress ratio, a tunnel excavation span and a tunnel burial depth; establishing a coordinate system by taking the surrounding rock strength-stress ratio as an abscissa and a function of the tunnel excavation span and the tunnel burial depth as an ordinate, and determining a value range of the abscissa and the ordinate; taking the structure load value as the basis of the design partition, and determining the structure load value range, the characteristic value, the number of the design partitions and the boundary position based onthe value ranges of the horizontal coordinate and the vertical coordinate; determining structure design parameters, section curvature optimization measures and auxiliary structure measures of each design subarea; and completing the extruded surrounding rock tunnel structure design chart. The method provided by the invention can quickly determine support lining parameters and auxiliary structure measures, and has the advantages of intuition, simplicity, quickness and accuracy.

Description

technical field [0001] The invention relates to the technical field of tunnel design, in particular to a design method for a tunnel structure with extruded surrounding rock. Background technique [0002] At present, the tunnels constructed by the mining method mostly adopt the composite lining structure. The composite lining structure is composed of the initial support, the secondary lining and the waterproof layer laid between them. Among them, the initial support is composed of bolts, shotcrete, steel arches, steel mesh and other support forms and one or more combinations, also known as bolt-and-shot support; the secondary lining is cast-in-place concrete or RC. [0003] At present, in the design method of tunnel composite lining structure, there is no effective design method and calculation method for composite lining structure considering both primary support and secondary lining. Generally, primary support and secondary lining are considered separately. The initial su...

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Problems solved by technology

[0015] 1. The foreign Norwegian method design chart is based on the Q surrounding rock classification system, which is not applicable to the classification method based on the stability of surrounding rock in my country, and it is only applicable to the Norwegian method with shotcrete as the main force-bearing structure. rock type, not for a specific surrounding rock condition;

[0016] 2. The design method of engineering analogy + load structure method to calculate internal force + strength check currently used at home and abroad is suitable for general surrounding rock conditions, not suitable for extrusive surrounding rock

When using the engineering analogy + load structure method to calculate the internal force + strength check method to design the tunnel structure with extrusive surrounding rocks, it is necessary to draw up sections and multiple trial calculations of structural parameters, the calculation process is complicated, and it is uncertain when to use multi-layer Auxiliary structural measures such as support and yield support

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