Tian H.-M.,CAS Wuhan Institute of Rock and Soil Mechanics |
Chen W.-Z.,CAS Wuhan Institute of Rock and Soil Mechanics |
Chen W.-Z.,Yanzhou Coal Mining Company Ltd |
Xiao Z.-L.,CAS Wuhan Institute of Rock and Soil Mechanics |
And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2015
The stress relaxation properties of soft rock are an important aspect of its long-term mechanical properties, which are very important to keep soft rock tunnel long-term stability. The triaxial stress relaxation tests on argillaceous siltstone are carried out under confining pressures from 15 to 35 MPa. The relaxation curves can be divided into two stages: the transient relaxation and steady relaxation. When the stress relaxation starts with the initial deviatoric stress, which is much lower than the peak stress of the specimen, the relaxation is mainly composed of transient relaxation. However, when the initial deviatoric stress approaches to the peak stress of the specimen, obvious steady relaxation is observed. The comparisons of relaxation curves obtained from specimens under different confining pressures show that when the initial deviatoric stress is much lower than the peak stress of the specimen, the confining pressure has little effect on the relaxation behaviour of the specimen; and when the initial deviatoric stress approaches to the peak stress of the specimen, the relaxation stress decreases with the increase of the confining pressure. Based on the analysis on the results of triaxial relaxation tests, the Nishihara model is employed to describe the relaxation behaviour of argillaceous siltstone, and the comparisons between numerical and measured relaxation stress indicate the rationality of the Nishihara model. ©, 2015, Chinese Society of Civil Engineering. All right reserved.
Wang E.H.,Guizhou Highway Engineering Group Co. |
Wang Z.D.,Wuhan University of Technology |
Jiang L.M.,Wuhan Building Material Industry Design and Research Institute Co. |
Hao L.,Shenzhen Engineering Design Co. |
Ran A.,Guizhou Highway Engineering Group Co.
Applied Mechanics and Materials | Year: 2014
Discrete element software is used to simulate the excavation of a rock slope in Puli-Xuanwei Expressway in Yunnan Province. Through monitoring displacement development characteristics in different positions of slope, the result shows that the minimum horizontal displacement under excavation exists in the top of the slope, meanwhile the maximum horizontal displacement occurs in the foot and waist of the slope, and the maximum vertical displacement occurs in the top of the slope. Comparing rock slope in such conditions as different stratum angles, directions, rock characteristics and thickness, it concludes possible failure modes of slope and the variation law of safety coefficient under different conditions. This paper is instructive and offers reference for the practical engineering. © (2014) Trans Tech Publications, Switzerland.
Jiang X.-B.,Guizhou Highway Engineering Group Co. |
Wang Q.,Southwest Jiaotong University
Bridge Construction | Year: 2013
To have an understanding of the mechanical mechanism and behavior of the temporary connectors used for long span suspension bridge under the action of strong wind, the analysis of the mechanical mechanism and behavior of the connectors was carried out by way of example of the Xihoumen Bridge of Zhoushan Mainland and Islands Link Project. On condition that the factor of wind resistance was considered, the design methods and layout schemes for the connectors of such type were studied. The working mechanism of the connectors was analyzed, using the global model and the distribution ratios of tie rod axial forces of the connectors at the different locations were acquired. The wind-induced internal forces of the girder blocks of the different construction stages were transferred into the axial forces of the connectors, the axial forces were then taken as the action load and the local forces of the load-bearing plates of the connectors were calculated, using the elastoplastic analysis method. In terms of the mechanical characteristics of the connectors, the measure of locally reinforcing the load-bearing plates by the circular steel plates was proposed and in the areas of the girder blocks with great internal forces, the optimization layout scheme of adding the connectors according to the need was proposed as well. For the installed girder blocks nearby the north and south towers, the measure of reinforcing the girder blocks by strongbacks was added. In the practical application, the correctness and effectiveness of the optimization layout scheme were hence verified.
Fu W.-S.,Bridge Science Research Institute Ltd. |
Tian H.-S.,Guizhou Highway Engineering Group Co. |
Sun Z.,Urban Road and Bridge Toll and Management Center
Bridge Construction | Year: 2013
To study the methods for assessment and strengthening of the deteriorations (e.g. the concrete cavity and debonding in the steel tubes) of the main arch ribs, the critical load-bearing parts of the concrete-filled steel tube (CFST) arch bridge, an existing CFST arch bridge (a thrust and hingeless deck arch bridge with net span length 160 m) was cited as example. The concrete density in the steel tubes of the arch ribs of the bridge was inspected by the combined method of hammering and ultrasonic detection and the mechanical behavior of the global structure of the bridge was tested by the dynamic and static load tests. According to the mechanical behavior of the tested structure, the finite element software was used to analyze the stress of the concrete in the steel tubes in different status and with reference to the analysis, the deteriorations of the main arch ribs were assessed. The results of the assessment show that the major deterioration of the arch ribs is the weakening of the local concrete sections caused by the concrete debonding in the steel tubes and the abnormally great checking coefficients of the midspan sections of the arch ribs only denotes the local deterioration of the structure. Based on the assessment, the way of strengthening of the arch ribs by grouting has been proposed and the mechanical behavior of the global structure after strengthening can meet the designed load requirements.
Huang F.,GuiZhou Highway Engineering Group Co |
Tan D.-L.,Chengdu University of Technology |
Yang D.-L.,GuiZhou Highway Engineering Group Co
Wutan Huatan Jisuan Jishu | Year: 2011
Through high - density electrical method, some section of roadbed and slope of die survey results in Biwei highway show diat the mediod can effectively identify bad geologic body in the work area, including faults, karst, landslides, and provide an accurate geological data for die further construction and management of die project. The high-density electrical field operations use a short time, a large amount of data can be collected and die results of data processing are intuitive widi image format which is easy to interpret. So it is one of the effective means of engineering geological investigation of the disaster.
Yang D.-L.,GuiZhou Highway Engineering Group Co |
Ge B.,State Key Laboratory of Geohazard Prevention and Geoenvironment Protection |
Ge B.,Chengdu University of Technology |
Huang F.,GuiZhou Highway Engineering Group Co
Wutan Huatan Jisuan Jishu | Year: 2011
With the investment in the mountain highway construction investment recent years, the research on slope of high-risk disease becomes increasingly important. As is known to all, mountainous topography general ups and downs bigger, and geological conditions are radier complicated, where some geological disasters easlily develop, such as landslide, collapse accumulation, geological hazards, karst collapse etc. Effectively and accurately detecting the space distribution features of geological disasters to help design and safety management is extremely important. The paper introduced a high - density electrical method in detecting the geological disasters in slope application which based on a highway landslide in Guizhou prospecting application, and used drilling data of detection results for verifying, which proved the effectiveness of high-density resistivity method in the exploration of geological disasters in slope detecting.