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| MODEL TESTS FOR MECHANICAL RESPONSE OF BEDDING ROCK SLOPE UNDER DIFFERENT RAINFALL CONDITIONS |
| LI Longqi1，2，LUO Shuxue2，WANG Yunchao2，WEI Wenkai2，LI Chugen3 |
(1. School of Civil Engineering，Chengdu University of Technology，Chengdu，Sichuan 610059，China；
2. School of Civil Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China；
3. China Railway Eryuan Engineering Group Co.，Ltd.，Chengdu，Sichuan 610031，China) |
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Abstract The rain spraying and fiber grating monitoring were used in a geomechanical modeling test under different rainfall and support conditions to investigate the mechanical influences of different rainfall conditions on the bedding rock slope. The physical data including the displacements，the pore pressures and the supporting structure?s internal forces were analyzed. It was found that the displacement and the pore pressure variations occurred mainly at the surface of slope for the unsupported slope under the heavy rainfall condition within a short time，while the displacements became larger and the pore pressure dissipated faster in the front of the slope surface after the rain. The accumulation and dissipation of excess pore water pressure were the main factors influencing the slope stability for this type of slope. For the unsupported slope under light rainfall during a long period，the displacements and pore water pressures also occurred beneath the slope surface. A large growth rate of displacements and a smaller decreasing rate of pore water pressure dissipation remained after the rain. The soften effect on interlayers due to rain infiltration may be the main influential factors to affect the slope stability in this case. While in the case of the supported slope, the displacements and the pore pressures were much smaller due to the restriction on the crack development which reduced the rain infiltration. The stresses of the supporting structure reached stable values quickly under the heavy rainfall condition within a short period and are adjusted slowly under the light rainfall condition within a long period. The maximum values of slope thrust 6 hours after the raining appeared in the different positions at different rainfall conditions. The maximum value occurred at the top of the supporting structure under the short and heavy rainfall condition and occurred at the middle of the supporting structure under the long and light rainfall condition. The magnitude of the latter was about 1.5–1.7 times of the former at the same location.
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Received: 04 June 2013
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2014, Vol. 33 
