Model Test Study on Spatial Deformation Law of Surrounding Rock for Super-Large Section and Shallow Buried Tunnels

2018 ◽  
Vol 42 (3) ◽  
pp. 20170243 ◽  
Author(s):  
Cong Liu ◽  
Shucai Li ◽  
Zongqing Zhou ◽  
Liping Li ◽  
Kang Wang ◽  
...  
2019 ◽  
Vol 136 ◽  
pp. 04024
Author(s):  
Yuwen Wang ◽  
Xiang Yang Cui ◽  
Hongyan Guo ◽  
Ke Li

Taking several tunnels under construction of a highway as the research object, the ultimate displacement of four buried depth sections of 0-50, 50-100, 100-300, 300-500 m in the surrounding rock of grade III, IV and V is numerically simulated by three-step and seven-step excavation method, middle-wall method, cross-middle-wall method and double-side-wall guide pit method for initial support of large-section highway tunnels. Through analysis, the deformation law of tunnel surrounding rock is obtained: under the same buried depth, the displacement ultimate displacement of the two-sided guide pit method and the cross-middle-wall method is the largest, the middle-wall method is the second, and the three-step seven-step excavation method is the smallest. Through the analysis and collation of the measured data obtained by monitoring and measurement of each construction method in the construction site, the surrounding rock deformation datum values of large-span and large-section tunnel under each construction method are obtained.


2011 ◽  
Vol 71-78 ◽  
pp. 1870-1874
Author(s):  
Jin Xing Lai ◽  
Cheng Bing Gong ◽  
Yan Song Wang

Based on similarity theory, the systemic analysis for the distribution characteristics of tunnel temperature field in two different working conditions of having no thermal insulation and installing PU as insulator is progressed by using manufactured model test platform in order to realize the tunnel temperature field rule in cold regions with or without thermal insulation and the influence of thermal insulation layout pattern on insulating effect. The results show that the temperature variation conforms to the “tunnel freeze-thaw circle” theory without thermal insulation, and the surrounding rock maintains negative temperature all the time in the low temperature environment; the internal temperature field of surrounding rock plays a decisive role on the surface temperature of surrounding rock, which keeps above 0°C after the layout of thermal insulation with appropriate material and thickness.


2013 ◽  
Vol 353-356 ◽  
pp. 1411-1416
Author(s):  
Jun Sheng Chen ◽  
Shu Zhuo Liu ◽  
Ren Guo Gu ◽  
Ying Guang Fang ◽  
Hai Hong Mo

The profile layout rationality and internal stress structure of a large-section cable tunnel and a cable-laying scheme at splicing locations were studied through full-scale model test. The full scale shield tunnel which the diameter was 6m was built on the ground. The model tests test the displacement of cable bearers, the coupling area between horizontal beam and steel ring, the coupling area between horizontal beam and steel pillar, edge beam and center beam under design loads, and the safety and reliability of an arc steel framing system that supports the cable load inside the cable tunnel during the operation stage were demonstrated. The cable-laying schemes for the cross section and straight-through-type and T-type couplings of a large-section cable tunnel were optimized through experiment on actually laid-out cables. For the section layout of a large-section cable tunnel, it is believed that the double-deck scheme prevails over the single-deck scheme, and such a cable-splicing scheme can meet the cable-laying requirement.


2015 ◽  
Vol 52 (6) ◽  
pp. 485-493 ◽  
Author(s):  
Dae Hyuk Kim ◽  
Inn-Duk Seo ◽  
Key-Pyo Rhee ◽  
Nakwan Kim ◽  
Jin-Hyung Ahn
Keyword(s):  

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.


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