Study of the Failure Mechanism and Progressive Failure Process of Intact Rock Patches of Rock Slope with Weak Surfaces

2016 ◽  
Vol 50 (4) ◽  
pp. 951-966 ◽  
Author(s):  
Xiao-Hua Pan ◽  
Hong-Yue Sun ◽  
Zhi-Jun Wu ◽  
Qing Lü
2006 ◽  
Vol 306-308 ◽  
pp. 1461-1466 ◽  
Author(s):  
Y.Q. Liu ◽  
Hai Bo Li ◽  
H.C. Dai ◽  
Jun Ru Li ◽  
Qing Chun Zhou

The progressive failure process of a layer rock slope under explosions is simulated using two-dimensional Universal Distinct Element Code (UDEC). It is shown that the failure process of the slope can be divided into three phases, the formation and growth of local failure area as well as coalescence of sliding plane. In addition, the displacement components of a critical point of the slope are also suggested to be a progressive process.


2014 ◽  
Vol 574 ◽  
pp. 89-95 ◽  
Author(s):  
Ya Qun Liu ◽  
Hai Bo Li ◽  
Xiang Xia ◽  
Bo Liu ◽  
Qi Tao Pei

The dynamic response of an idealized layered rock slope with a single joint subjected to seismic loads is investigated using the three dimensional distinct element code in the present study. Based on the numerical modeling, the variations of the stresses of the blocks close to the joint and the deformation of the joint are discussed, and the progressive failure mechanism of the slope is analyzed. It is found that, with the increasing excitations, the tensile stresses and the areas of tension zones in the upper part of the slope near the joint have increased gradually. In addition, the normal displacement at the upper part of the joint also becomes larger and larger, which leads to the gradual split of the upper part of joint. Hence the contact area for blocks at both sides of the joint has decreased, which gradually results in the decrease of the cohesion of the joint. When the induced shear stress for the joint under the applied excitations exceeds its shear strength, the potential sliding blocks will slip along the joint. The results in this paper may provide references for the study on failure mechanism of complicated layered rock slopes subjected to dynamic loads.


2021 ◽  
Vol 28 ◽  
pp. 100529
Author(s):  
Yu Zhao ◽  
Quanmei Gong ◽  
Yaojie Wu ◽  
Zhiyao Tian ◽  
Shunhua Zhou ◽  
...  

Landslides ◽  
2021 ◽  
Author(s):  
Chiara Crippa ◽  
Elena Valbuzzi ◽  
Paolo Frattini ◽  
Giovanni B. Crosta ◽  
Margherita C. Spreafico ◽  
...  

AbstractLarge slow rock-slope deformations, including deep-seated gravitational slope deformations and large landslides, are widespread in alpine environments. They develop over thousands of years by progressive failure, resulting in slow movements that impact infrastructures and can eventually evolve into catastrophic rockslides. A robust characterization of their style of activity is thus required in a risk management perspective. We combine an original inventory of slow rock-slope deformations with different PS-InSAR and SqueeSAR datasets to develop a novel, semi-automated approach to characterize and classify 208 slow rock-slope deformations in Lombardia (Italian Central Alps) based on their displacement rate, kinematics, heterogeneity and morphometric expression. Through a peak analysis of displacement rate distributions, we characterize the segmentation of mapped landslides and highlight the occurrence of nested sectors with differential activity and displacement rates. Combining 2D decomposition of InSAR velocity vectors and machine learning classification, we develop an automatic approach to characterize the kinematics of each landslide. Then, we sequentially combine principal component and K-medoids cluster analyses to identify groups of slow rock-slope deformations with consistent styles of activity. Our methodology is readily applicable to different landslide datasets and provides an objective and cost-effective support to land planning and the prioritization of local-scale studies aimed at granting safety and infrastructure integrity.


2019 ◽  
Vol 92 ◽  
pp. 16010
Author(s):  
Benjamin Cerfontaine ◽  
Jonathan Knappett ◽  
Michael Brown ◽  
Aaron Bradshaw

Plate and screw anchors provide a significant uplift capacity and have multiple applications in both onshore and offshore geotechnical engineering. Uplift design methods are mostly based on semi-empirical approaches assuming a failure mechanism, a normal and a shear stress distribution at failure and empirical factors back-calculated against experimental data. However, these design methods are shown to under- or overpredict most of the existing larger scale experimental tests. Numerical FE simulations are undertaken to provide new insight into the failure mechanism and stress distribution which should be considered in anchor design in dense sand. Results show that a conical shallow wedge whose inclination to the vertical direction is equal to the dilation angle is a good approximation of the failure mechanism in sand. This shallow mechanism has been observed in each case for relative embedment ratios (depth/diameter) ranging from 1 to 9. However, the stress distribution varies non-linearly with depth, due to the soil deformability and progressive failure. A sharp peak of normal and shear stress can be identified close to the anchor edge, before a gradual decrease with increasing distance along the shear plane. The peak stress magnitude increases almost linearly with embedment depth at larger relative embedment ratios. Although further research is necessary, these results lay the basis for the development of a new generation of design criteria for determining anchor capacity at the ultimate limiting state.


2021 ◽  
pp. 105678952110014
Author(s):  
Jichang Wang ◽  
Xiaoming Guo ◽  
Nailong Zhang

In this research, experiments and numerical simulations are employed to research the failure process of concrete. Fracture experiments on three-point bending (TPB) concrete beams with a prefabricated edge notch at the middle of the beam bottom are performed using a modified rigid testing instrument. The characteristics of the crack and section are analyzed, including the crack tensile opening displacement, crack length and width, and crack faces characteristics. Also, the full curves of the force-crack tensile opening displacement (CMOD) and force-deflection of the TPB beams with the prefabricated edge notch after breakage are obtained. The phase field (PF) damage model is applied to the mixed-mode and mode-I failure processes of concrete structures through the ABAQUS subroutine user defined element (UEL). The crack path and the full curves of force-CMOD and force-deflection obtained by numerical calculations are consistent with the experimental results and the calculated results of other researchers. The influences of the mesh sizes, initial lengths, and notched depths on the TPB beam of concrete are also analyzed.


2012 ◽  
Vol 6 (6) ◽  
pp. 2147-2163 ◽  
Author(s):  
K. Ma ◽  
C. A. Tang ◽  
L. C. Li ◽  
P. G. Ranjith ◽  
M. Cai ◽  
...  

2011 ◽  
Vol 90-93 ◽  
pp. 74-78 ◽  
Author(s):  
Jun Hu ◽  
Ling Xu ◽  
Nu Wen Xu

Fault is one of the most important factors affecting tunnel instability. As a significant and casual construction of Jinping II hydropower station, when the drain tunnel is excavated at depth of 1600 m, rockbursts and water inrush induced by several huge faults and zone of fracture have restricted the development of the whole construction. In this paper, a progressive failure progress numerical analysis code-RFPA (abbreviated from Rock Failure Process Analysis) is applied to investigate the influence of faults on tunnel instability and damaged zones. Numerical simulation is performed to analyze the stress distribution and wreck regions of the tunnel, and the results are consistent with the phenomena obtained from field observation. Moreover, the effects of fault characteristics and positions on the construction mechanical response are studied in details. Some distribution rules of surrounding rock stress of deep-buried tunnel are summarized to provide the reasonable references to TBM excavation and post-support of the drain tunnel, as well as the design and construction of similar engineering in future.


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