Physical model test on deformation and failure mechanism of deposit landslide under gradient rainfall

Author(s):  
Huanling Wang ◽  
Zihua Jiang ◽  
Weiya Xu ◽  
Rubin Wang ◽  
Weichau Xie
2021 ◽  
Vol 31 (2) ◽  
pp. 291-302
Author(s):  
Xiaoming Sun ◽  
Chengwei Zhao ◽  
Yong Zhang ◽  
Feng Chen ◽  
Shangkun Zhang ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Zhibiao Guo ◽  
Jinyan Fan ◽  
Fengnian Wang ◽  
Hongbo Zhou ◽  
Wei Li

The Minxian tunnel is a key engineering of the Weiyuan-Wudu expressway that is excavated in layered jointed carbonaceous slate rock mass. During the construction process, the surrounding rocks of the tunnel encountered serious large deformations and failure, which brought about great difficulties to the safety and cost of the tunnel. In order to study the deformation and failure mechanism of the surrounding rocks, a physical model test was conducted, and integrated methods including strain gauges, a digital camera, and noncontact full-field digital imaging correlation technique were used to record the response information of the surrounding rocks. The evolution process of surrounding rocks failure was simulated successfully in the model test, and the deformation characteristics were basically consistent with the actual engineering. The modelling results show that concentrated stresses in the surrounding rocks were very uneven due to developed stratified and jointed rock mass structure. The maximum and minimum concentrated stresses appeared at the vault of the tunnel and left of inverted arc area, and concentration factors were 3.11 and 1.98, respectively. The main forms of surrounding rocks deformation and failure were large area spalling of surface, severe circumferential fractures, serious bending deformations of thin rock layers, and collapse of overlying strata. The maximum displacements occurred at left sidewall and right shoulder of the tunnel and the corresponding actual displacements were 460 mm to 500 mm. Caving and failure took place firstly at several key positions with maximum concentrated stresses or displacements and subsequently gave rise to massive collapse of surrounding rocks.


2012 ◽  
Vol 170-173 ◽  
pp. 1147-1150
Author(s):  
Hui Ming Tang ◽  
Xin Li Hu ◽  
Cheng Ren Xiong

Physical model experiments are conducted to study the potential deformation and failure mechanism of Zhaoshuling landslide in the reservoir area of the Three Gorges project under the action of reservoir impoundment, water level fluctuation, building load and possible seismic load. Dial gauges, grid lines and digital cameras are used to monitor and record the deformations and displacements of the models. Research results indicate that the landslide will be basically stable while covered with seven-floor buildings whether the water level be at 145m or 175m, or falls abruptly from 175m to 145m. When the intensity of an earthquake is beyond certain degree, the rock mass will deforms and lose stability partly; and its stability will be worst when the water level falls from 175m to 145m, stability will be better when the level being at 145m and it will be best when the level being at 175m. It also indicate from deformation and failure mechanism revealed by the experiments that the best position of reinforcement measures is in Yanjiang Avenue, and the sliding resistance of the rock mass in the front part of the landslide can be used.


2011 ◽  
Vol 90-93 ◽  
pp. 2363-2371
Author(s):  
Bin Wei Xia ◽  
Ke Hu ◽  
Yi Yu Lu ◽  
Dan Li ◽  
Zu Yong Zhou

Physical models of layered rock mass with different dip angles are built by physical model test in accordance with the bias failure characteristics of surrounding rocks of layered rock mass in Gonghe Tunnel. Bias failure characteristics of surrounding rocks in thin-layered rock mass and influences of layered rock mass dip angle on stability of tunnel are studied. The research results show that failure characteristics of physical models generally coincide with those of surrounding rocks monitored from the tunnel site. The failure regions of surrounding rock perpendicular to the stratification planes are obviously larger than those parallel to. The stress distributions and failure characteristics in the surrounding rocks are similar to each physical model of different dip angles. The stress distributions and failure regions are all elliptic in shape, in which the major axis is in the direction perpendicular to the stratification planes while the minor axis is parallel to them. As a result, obvious bias failure of surrounding rocks has gradually formed. The physical model tests provide reliable basis for theoretical analysis on the failure mechanism of deep-buried layered rock mass.


Author(s):  
Jijian Lian ◽  
Junling He ◽  
Fang Liu ◽  
Danjie Ran ◽  
Xiaoqun Wang ◽  
...  

Flood discharge atomization is a serious challenge that threatens the daily lives of the residents around the dam area as well as the safety of the water conservancy project. This research aims to improve the prediction accuracy of the stochastic splash model. A physical model test with four types of flip bucket is conducted to obtain the hydraulic parameters of the impinging outer edge of the water jet, the relationship of the splashing droplet diameter with its corresponding velocity, and the spatial distribution of the downstream nappe wind. The factors mentioned above are introduced to formulate the empirical model. The rule obtained from the numerical analyses is compared with the results of the physical model test and the prototype observations, which yields a solid agreement. The numerical results indicate that the powerhouse is no longer in the heavy rain area when adopting the flip bucket whose curved surface is attached to the left wall. The rainfall intensity of the powerhouse is significantly weaker than that of other types under the designed condition, so we choose it as the recommended bucket type. Meanwhile, we compare the rainfall intensity distribution of the original bucket and the recommended bucket under different discharge which rates ranging from 150.71 to 1094.9 m3/s. It is found that the powerhouse and the owner camp are no longer in the heavy rain area under all of the working conditions. Finally, it is shown that the atomization influence during the flood discharge can be reduced by using the recommended bucket.


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