scholarly journals Formation Mechanism and Stability Analysis of the Hejia Landslide

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hao Zhang ◽  
Zaiqiang Hu ◽  
Xingzhou Chen ◽  
Hongru Li
Keyword(s):  
Formation Mechanism ◽  
Soft Rock ◽  
Normal Operation ◽  
Hydropower Station ◽  
Rock Interaction ◽  
Reservoir Impoundment ◽  
Layered Slope ◽  
Geological Conditions ◽  
Slope Structure ◽  
The Stability

The existing research data show that, after reservoir impoundment, due to the repeated rise and fall of water level and water-rock interaction, the mechanical parameters of landslide are reduced, which will have an adverse effect on the stability of landslide. Therefore, sufficient attention must be paid to the stability of slope after reservoir impoundment. Hejia landslide is the largest landslide near the bank of Miaojiaba hydropower station, and its stability plays an important role in the normal operation of the hydropower station. Through field investigation and analysis of regional geological conditions, it is concluded that Hejia landslide is a large-scale landslide, through long-term sliding-bending deformation; it is generated from the external hard rock with thick layers and sliding zone for layered soft rock; the formation mechanism of landslide is as follows: (1) high-steep and hard-soft layered slope is the slope structure condition that caused the large landslide; (2) the existence of thick soft rock belt provides material conditions for the formation of slip surface; (3) certain air conditions provide displacement space for the separation and disintegration of the sliding body, and the landslide is stable at present. Numerical analysis results show that reservoir impoundment will adversely affect the stability of landslide. In order to ensure the normal operation of power station, certain engineering measures must be taken to treat Hejia landslide. After taking measures, years of monitoring data show that the deformation of Hejia landslide tends to be stable, and the current operation is normal, indicating that the engineering treatment measures are reasonable and feasible.

Research on the Bearing Capacity for Rock Bolt Crane Girder in the Underground Powerhouse of Large Hydropower Station

2011 ◽  
Vol 255-260 ◽  
pp. 3563-3567
Author(s):  
Jian Bin Xie ◽  
Tian Chun He ◽  
Ji Yao ◽  
Chen Bo Zi
Keyword(s):  
Bearing Capacity ◽  
Design Criterion ◽  
Rock Bolt ◽  
Hydropower Station ◽  
Safe Operation ◽  
Underground Powerhouse ◽  
Geological Conditions ◽  
Enterprise Standard ◽  
The Stability ◽  
Rock Section

In this paper, according to the reality that there is no mature Chinese national design criterion but partial enterprise standard for rock bolt crane girder in the underground powerhouse of large hydropower station up to now. Based on the geological conditions, the rock bolt crane girder was designed by using method of rigid body equilibrium. The reinforced anchoring measures for rock bolt crane girder in undesirable geology were studied subsequently by the experience of analogous projects. The stability of rock bolt crane girder in underground powerhouse was analyzed and evaluated by Finite Element Method (FEM). Then the bearing capacity of crane beam was researched by means of bearing testing. The results show FEM is practicable to evaluate the stability of the rock bolt crane girder and to guide the rock bolt crane girder designing. The results also show the reinforced anchoring measures are appropriate to displace the undesirable surrounding rock section by using concrete. The results of bearing testing show that the design of rock bolt crane girder and its anchoring measures are rational, and crane girder can meet to the requirement of safe operation.

Formation and Stablity of the Sky Pond Landslide Dam, China

2011 ◽  
Vol 243-249 ◽  
pp. 3189-3200 ◽  
Author(s):  
Yan Hui Song
Keyword(s):  
Yellow River ◽  
Limit Equilibrium ◽  
Landslide Dam ◽  
Equilibrium Analysis ◽  
Qualitative Assessment ◽  
Hydropower Station ◽  
The Yellow River ◽  
Geological Conditions ◽  
Dammed Lake ◽  
The Stability

The Sky Pond landslide dam is located in Muchang valley, a branch of the Yellow River branches. From this point it is about 6Km to the mouth of the valley from where the Yellow River flows 0.8Km downwards to the planned Jishi gorge hydropower station. The Sky Pond landslide dam is actually formed by two landslides from both the left and right bank slopes and completely blocks the seasonal river channel. The volume of the landslide dam is about 14 millions m3 with 2.37 millions m3 water stored in the dammed lake under the condition of perennial mean water level. Because (1) the dam body is large in width and thickness; (2) the dammed lake water is small both in volume and weight compared to the landslide dam; (3) recharge to the dammed lake is basically the same as the discharge every year; and (4) there is a natural spillway in the dam body, the landslide dam is present at least 750 years after its formation. Although landslide dams which have existed for several hundreds to thousands of years are generally considered as stable, there are remains which may fail catastrophically. In order to analyze the stability of the Sky Pond landslide dam and provide justification for the future engineering decisions, this paper describes the engineering geological conditions near the landslide dam and the characteristics of the dam body, and a detailed discussion of the formation mechanism of the landslide. Based on engineering geology investigation, a qualitative assessment of the stability of the dam and an analysis of the probability of dam overtopping and piping is carried out. Limit equilibrium analysis has been used to calculate the stability of the dam slope under various operational conditions. Results of the stability analyses indicate that the Sky Pond landslide dam should remain stable and does not present a potential theat to the planned hydropower station.

Analysis for the Seepage Stability of the Upstream Cofferdam of One Hydropower Station

2013 ◽  
Vol 441 ◽  
pp. 286-290
Author(s):  
Yu Lin Yuan ◽  
Yun Feng Peng
Keyword(s):  
Safety Factor ◽  
Theoretical Basis ◽  
Circle Method ◽  
Control Design ◽  
Hydropower Station ◽  
Software Analysis ◽  
Seepage Control ◽  
Geological Conditions ◽  
The Stability

According to the geological conditions of upstream cofferdam and foundation of the hydropower station, analysis for the seepage of the upstream cofferdam used SEEP/W module of Geo-studio software. Analysis for the stability used SLOPE/W module with Swedish circle method and Bishop method. Safety factor of the upstream and downstream in different conditions was obtained. The results show that the design of the upstream cofferdam was reasonable, and it will provide theoretical basis for Seepage control design of cofferdam.

Numerical Simulation of Excavation of Abutment Slope at Left Bank in Dagangshan Hydropower Station

2012 ◽  
Vol 238 ◽  
pp. 313-316
Author(s):  
Kun Yang ◽  
Zhi Chao Ma ◽  
Hao Han
Keyword(s):  
Element Model ◽  
Hydropower Station ◽  
Left Bank ◽  
Geological Conditions ◽  
Potential Failure ◽  
Deformation Stress ◽  
The Stability ◽  
Dagangshan Hydropower Station ◽  
Failure Location ◽  
The Finite Element Model

The abutment slope at left bank in Dagangshan hydropower station has complex geological conditions with deep fractures, developed faults and unloading crack. The excavation will influence the stability of the slope. To evaluate the slope stability, the finite element model of this abutment slope was built in this paper to study the deformation, stress and plastic zone distribution of the slope during the excavation. The potential failure location of the slope is forecasted, some suggestions are proposed to be helpful to keep the stability of the slope.

scholarly journals Influence of Discontinuities on Rock Failure under Blasting at Shuangjiangkou Hydropower Station

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xi Zhao ◽  
Bangbiao Wu ◽  
Liyuan Yu ◽  
Tieshuan Zhao ◽  
Zhonghua Hu
Keyword(s):  
Impact Resistance ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Dynamic Tests ◽  
Support Design ◽  
Failure Characteristics ◽  
Underground Caverns ◽  
Geological Conditions ◽  
The Stability ◽  
Surrounding Rock Deformation

The underground caverns of Shuangjiangkou hydropower station are under complex geological conditions. During excavation, the stability of the tunnels is severely affected by problems, such as blasting impact and excavation unloading, resulting in abnormal deformation at different locations. On the basis of on-site measurement, the characteristics of rocks at the main powerhouse and the main transformer room are compared through dynamic tests, and a numerical model is established using discrete element method (DEM) to analyze the special influence of fault SPD9-f1 on the deformation after excavation. It is revealed that the surrounding rock of the main powerhouse has stronger impact resistance than that of the main transformer room and that the existence of fault SPD9-f1 accounts for the abnormal deformation. In this study, the failure characteristics and mechanism of surrounding rock deformation controlled by stress and fault are revealed, providing important references for the subsequent excavation and support design of underground projects.

Monitoring Analysis of the Underground Cavities in Guandi Hydropower Station during the Construction Period

2011 ◽  
Vol 368-373 ◽  
pp. 2925-2931
Author(s):  
Chun Yu Gao ◽  
Jian Hui Deng ◽  
Fan Li Meng
Keyword(s):  
Surrounding Rock ◽  
Hydropower Station ◽  
Water Control ◽  
Maximum Deformation ◽  
Monitoring Design ◽  
Geological Conditions ◽  
Underground Cavities ◽  
The Stability ◽  
Tail Water ◽  
The Right

The underground cavities of the Guandi Hydropower Station comprise four pressure division tunnels, a generator chamber, a main transformer chamber, a tail water control chamber and two tail water tunnels and arrange in the basalt mountain on the right bank of the dam. Based on the brief introduction of cavity arrangement, geological conditions, monitoring design and execution, the deformation magnitude and deformation characteristics of the three major cavities are focused on analyzing. The stability of the cavities is evaluated. The quality of the surrounding rock masses of the underground cavities of the Guandi Hydropower Station is good and the deformation is normally less than 30mm. However, some parts have large deformation due to the influence of the structure surfaces and the maximum deformation is 61.49 mm. Most of the parts with larger deformation are the middle and upper positions of the side walls and rock anchor beam positions. The structure surfaces have noticeable action for controlling the surrounding rock mass deformation. The stability of the cavities is good.

scholarly journals Stability Analysis of Jointed Rock Slope by Strength Reduction Technique considering Ubiquitous Joint Model

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ruili Lu ◽  
Wei Wei ◽  
Kaiwei Shang ◽  
Xiangyang Jing
Keyword(s):  
Rock Slope ◽  
Reduction Method ◽  
Domain Size ◽  
Jointed Rock ◽  
Strength Reduction ◽  
Hydropower Station ◽  
Strength Reduction Method ◽  
Vertical Side ◽  
The Stability ◽  
Jointed Rock Slope

In order to study the failure mechanism and assess the stability of the inlet slope of the outlet structure of Lianghekou Hydropower station, the strength reduction method considering the ubiquitous joint model is proposed. Firstly, two-dimension numerical models are built to investigate the influence of the dilation angle of ubiquitous joints, mesh discretization, and solution domain size on the slope stability. It is found that the factor of safety is insensitive to the dilation angle of ubiquitous joints and the solution domain size but sensitive to the mesh discretization when the number of elements less than a certain threshold. Then, a complex three-dimension numerical model is built to assess the stability of the inlet slope of the outlet structure of Lianghekou Hydropower station. During the strength reduction procedure, the progressive failure process and the final failure surface of the slope are obtained. Furthermore, the comparison of factors of safety obtained from strength reduction method and analytical solutions indicates that the effect of vertical side boundaries plays an important role in the stability of jointed rock slope, and the cohesive force is the main contribution to the resistant force of vertical side boundaries.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.

scholarly journals Study on the Deformation Mechanism of Soft Rock Roadway under Blasting Disturbance in Baoguo Iron Mine

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hong-di Jing ◽  
Yuan-hui Li ◽  
Kun-meng Li
Keyword(s):  
Rock Mass ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Deformation Monitoring ◽  
Underground Mines ◽  
Blasting Vibration ◽  
Iron Mine ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to study the deformation mechanism of soft rock roadway in underground mines, it is necessary not only to study the influence of the dynamic disturbance caused by the cyclic mining blasting vibration on the stability of the soft rock roadway but also to study the degradation of the roadway surrounding rock itself and other factors. The paper presented a synthetic research system to investigate the factors that influence roadway rock structure deterioration in Baoguo Iron Mine. Firstly, the stability of rock mass was analyzed from the perspective of the physical and structural characteristics of the rock mass. Afterwards, according to monitoring data of mining blasting vibration, a suitable safety blasting prediction model for Baoguo Iron Mine was determined. And then, combining the results of mining blasting vibration monitoring and deformation monitoring, the effect of cyclic mining blasting on the stability of the soft rock roadway was obtained. By systematically studying the intrinsic factors of rock quality degradation and external environmental disturbances and their interactions, this paper comprehensively explores the deformation mechanism of soft rock roadway and provides the support for fundamentally solving the large deformation problems of soft rock roadway in underground mines.

Judgement Method for Surrounding Rock Stability of Guanjiao Tunnel Based on Catastrophe Theory

2011 ◽  
Vol 90-93 ◽  
pp. 2307-2312 ◽  
Author(s):  
Wen Jiang Li ◽  
Su Min Zhang ◽  
Xian Min Han
Keyword(s):  
Plastic Strain ◽  
Catastrophe Theory ◽  
Soft Rock ◽  
Surrounding Rock ◽  
In Situ Monitoring ◽  
Engineering Practice ◽  
Stability Of Surrounding Rock ◽  
The Stability ◽  
Rock Tunnel

The stability judgement of surrounding rock is one of the key jobs in tunnel engineering. Taking the Erlongdong fault bundle section of Guanjiao Tunnel as the background, the stability of surrounding rock during construction of soft rock tunnel was discussed preliminarily. Based on plastic strain catastrophe theory, and combining numerical results and in-situ data, the limit displacements for stability of surrounding rock were analyzed and obtained corresponding to the in-situ monitoring technology. It shows that the limit displacements obtained corresponds to engineering practice primarily. The plastic strain catastrophe theory under unloading condition provides new thought for ground stability of deep soft rock tunnel and can be good guidance and valuable reference to construction decision making and deformation managing of similar tunnels.

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