Research Institute of Highway Ministry of Transport

The 5Th Engineering Co., Ltd of China Railway 11Th Bureau Group

Chongbang Xu

Xiaojing Gao

Hao Wang

Lei Li

Xuan Zhang

Xuefeng Li

Hualao Wang

Xiao Xu

Ju Du

Ziteng Zheng

Youlin Qin

The present disclosure relates to the technical field of tunnel construction, in particular to a design method of a buffer layer with critical deformation of a tunnel initial support as a control target. The method includes the following steps: (1) establishing a mechanical model and calculating an ultimate bearing capacity of the tunnel initial support during critical damage based on a cusp catastrophe theory; (2) determining a critical deformation value of the tunnel initial support under the ultimate bearing capacity; (3) establishing a yielding control target of a tunnel buffer layer; (4) determining a performance index of the buffer layer according to the control target, and calculating corresponding index parameters. Compared with the prior art, the method has the following beneficial effects. The method aims to put forward the critical deformation value of the tunnel initial support under the ultimate bearing capacity, obtain an optimal yielding design parameters of the buffer layer by taking a compression and load transfer mode of the tunnel buffer layer as a link, and give a calculation method.

Method of buffer layer with critical deformation of tunnel initial support as control target

Provided is a perception evaluation method for a bearing capacity of a highway tunnel lining structure, including: from the load effect evolution state of surrounding rock and the decay mechanical state of a lining structure, the characterization index system of a highway tunnel bearing capacity is constructed; a characterization index inversion function relationship based on strain data of an inner surface of the highway tunnel lining is provided, a bearing capacity perception layout scheme of the tunnel structure is constructed accordingly, and a complete set of perception method for bearing capacity characterization indexes is obtained; then, by calculating a load effect function and a resistance effect function, the calculation and evaluation method of the tunnel structure bearing capacity.

Perception evaluation method for service performance of highway tunnel lining structure

Disclosed is a sulfate corrosion-resistant concrete, a method for optimizing proportion and application thereof. The concrete is formed by mixing and stirring base stocks, aggregates, admixtures, external additives and water. The base stock of the concrete is 17.4-17.5 parts of Portland cement; the aggregates include 38.9 parts of basalt with aggregate size of 5-10 mm and 33.1-33.2 parts of basalt medium sand; the admixtures are 1.9-1.95 parts of silica fume or fly ash, and further including 0.23-0.24 part of polycarboxylate water reducer and 1.34-1.35 part of sulfate corrosion-resistant liquid preservative. Optimized proportion method: according to the corrosion characteristics of sulfate and corrosion environment parameters, determine the composition and proportion of basic samples and comparison samples, make and cure sample components, test the deep components of the samples, and obtain the optimal composition and proportion according to the test results.

Sulfate corrosion-resistant concrete and method thereof for optimizing proportion and application

Provided is a method for analyzing the expansive stress and expansive strain of tunnel surrounding rock, including: (1) determining the surrounding rock state of the tunnel surrounding rock before expansion and the surrounding rock state after expansion; (2) according to the determined state of the surrounding rock, determining the expansive stress and expansive strain of the tunnel surrounding rock before expansion, and determining the expansive stress and expansive strain of the tunnel surrounding rock after expansion; (3) according to the surrounding rock state of the tunnel surrounding rock after expansion, determining the expansive deformation radius of the tunnel surrounding rock, so as to determine the expansive deformation displacement of the tunnel surrounding rock.

Method for analyzing the expansive stress and expansive strain of tunnel surrounding rock

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Beijing, China

Chongbang Xu