Qu M.,Southwest Jiaotong University |
Xie Q.,Southwest Jiaotong University |
Hu Y.,China Southwest Geotechnical Investigation and Design Institute Co. |
Li Z.,Southwest Jiaotong University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2015
A model test was performed to investigate the distribution of frost heaving force in tunnel lining. The surrounding rock (slate) of the tunnel was considered as a fissured medium and the frost heaving force caused by water migration in fissures was mainly studied. In the model, the fissures were implemented by laying permeable fabric in the surrounding rock, and the low temperature condition was realized by putting refrigeration equipment in the tunnel. The temperature and strain changes were measured by the resistance thermometer elements and the strain gages respectively. The model test results showed that the deformation in the inverted arch and near the foot of inverted arch was smaller but the deformation in the arch, the arch spring and the side wall was larger with the largest deformation in the side wall. The numerical simulation was applied for analysing the frost heaving force calculated by different frost models. The frost model for calculating the frost heaving force produced by the water-contained weathered rock layer was selected after the comparison of the results from experiments and numerical simulation, so that, the lateral and horizontal frost heaving force acting on the side wall of the tunnel lining, 0.9 MPa in entrance and 0.6 MPa in tunnel trunk was derived. ©, 2015, Academia Sinica. All right reserved.
Liu Y.,Chongqing University |
Liu X.,Chongqing University |
Yang Z.,Chongqing University |
Kang J.,China Southwest Geotechnical Investigation and Design Institute Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2016
Based on the elasto-plastic analysis of shear stress distribution in anchorage section, field destructive tests were carried out on the tension-concentrated anchor cable (TCAC), the tension-dispersed anchor cable (TDAC) and the pressure-dispersed anchor cable (PDAC). The comparative analysis was made regarding the shear stress distribution characteristics, the bearing capacity and the load-displacement curve. In the elastic stage, the peak shear stress appeared in the range of 0.5 m near the acting point of concentrated force and increased with the load growing. In the plastic period, debonding slippage occurred in the range of 0.5 m near the acting point of concentrated force, and the peak shear stress was shifted to the middle of anchorage body gradually. The residual shear stress on debonding section was about 1/3 of the peak value. TDAC has more uniform shear stress distribution and longer effective anchorage length, its carrying capacity was 31.1% higher than TCAC. Due to the radial expansion of anchorage body under pressure, the bond strength between PDAC and soil was improved, which made the PDAC's carrying capacity to increase by 17.7% compared with TDAC. It can be seen from the load-displacement curve that the PDAC had better displacement ductility and deformation resistivity, therefore, it had advantages in soil anchoring. © 2016, Science Press. All right reserved.
Zhou H.,Chengdu Center |
Wang C.,Chengdu Center |
Nie D.,Chengdu University of Technology |
Chen Z.,China Southwest Geotechnical Investigation and Design Institute Co.
Advances in Science and Technology of Water Resources | Year: 2016
Based on analysis and measurement of a geostress field at the dam site of the Jiangpinghe Hydropower Station, and comparison of calculated and measured stress at the points for stress fitting, inverse analysis of the initial geostress field at the dam site of the Jiangpinghe Hydropower Station was conducted using a three-dimensional numerical model with different boundary loading conditions. The results show that the initial geostress is low at the dam site of the Jiangpinghe Hydropower Station, the maximum principal stress is 2.5 MPa and its direction is N45°W, and the minimum principal stress is 1.5 MPa with a direction of N45°E. There is agreement between the calculated and measured stress at the points for stress fitting, indicating that the initial geostress field at the dam site obtained by inverse analysis is reasonable and conforms to the historical background of the geological structure. © 2016, Editorial Board of Advances in Science and Technology of Water Resources, Hohai University. All right reserved.
Ren X.-H.,Southwest Jiaotong University |
Zhao W.,Southwest Jiaotong University |
Wen J.-Q.,Southwest Jiaotong University |
Zheng L.-N.,China Southwest Geotechnical Investigation and Design Institute Co.
Geology in China | Year: 2013
Based on its morphological characteristics, this paper made a preliminary analysis of the genesis of the Ordovician gypsum-bearing breccia in North China. The geothermal characteristics during the formation stage of the gypsum-bearing breccia were analyzed with the numerical method, and the results show that the temperature condition for the dewatering of clay minerals and gypsum did exist. The pore gas pressure of gypsum-bearing mudstone at high temperature was analyzed with the experimental method, and the result shows that extremely high pore gas pressure will be generated by gypsum dewatering at high temperature. The SEM and energy spectrum analysis show that the mineral structure of gypsum is changed at high temperature. It is thus held that the gypsum-bearing breccia in North China might have been generated by air bunt.
Fei Z.,Kunming University of Science and Technology |
Fei Z.,China Southwest Geotechnical Investigation and Design Institute Co. |
Jing C.,Kunming University of Science and Technology |
Haiming L.,Kunming University of Science and Technology
Advanced Materials Research | Year: 2013
The bedding high rock slope is most likely to failure in the rock slopes. It is the sliding and bending deformation model (buckling failure) according to deformation characteristic of the north wing slope at the open-pit mine. Considering the influence of rocky self-weight, seismic force and groundwater, the failure mechanism of bedding high rock slope by energy method is researched on the basis of stability theory for elastic plane. And the critical length is obtained. Finally, the influences of model geometry on the critical length, such as the rock stratum dip angle, thickness and width length ratio, is analyzed. © (2013) Trans Tech Publications, Switzerland.