scholarly journals Sensitivity Analysis Of Influencing Factors On Tunnel Stability In Bad Geological Slope Sections

2020 ◽  
Vol 145 ◽  
pp. 02049
Author(s):  
Chao Qun Liu ◽  
WenQun Fu ◽  
Wei Luo ◽  
Dan Liu ◽  
Yang Sun
Keyword(s):  
Safety Factor ◽  
Influence Factors ◽  
Influential Factors ◽  
Orthogonal Test ◽  
Horizontal Distance ◽  
Research Results ◽  
Tunnel Stability ◽  
Calculation Results ◽  
The Stability ◽  
Design Construction

Based on a tunnel through slope of Yongji highway project, relying on ABAQUS geotechnical numerical analysis software, using the appearance of plastic penetration area for instablilty criterion, choosing 11 typical influential factors as independent variables to tunnel stability, the orthogonal test array L50(511) is used to analyze sensitivity of influence factors under evaluating indexes of safety factor to the tunnel stability and the maximum principal tensile on the inner surface of surrounding rock. Research results show that: there are some certain differences between calculation results of safety factor and maximum principal tensile, but overall presentation represents favorable consistency, and the sensitivity of influence factors to the stability of tunnel through unfavorable geological slope can be preferably annlyzed by orthogonal test. The influence of the cohesion of rock c, the horizontal distance d between tunnel centerline and slope toe, the inclination angle of slope α are significant. Comprehensive consideration of safety factor and maximum principal tensile of tunnel circumference is more perfect than one-sided safety factor when performing the analysis of tunnel stability. The research results of this paper can provide reference to design, construction of similar tunnels.

scholarly journals Effect of Slip Surface’s Continuity on Slope Dynamic Stability Based on Infinite Slope Model

Mathematics ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Chuanzheng Liu ◽  
Gang Wang ◽  
Wei Han
Keyword(s):  
Dynamic Stability ◽  
Stress Wave ◽  
Safety Factor ◽  
Slip Surface ◽  
Great Influence ◽  
Stress Wave Propagation ◽  
Surface Model ◽  
Infinite Slope ◽  
Research Results ◽  
The Stability

The slip surface is an important control structure surface existing in the landslide. It not only directly affects the stability of the slope through the strength, but also affects the stress field by affecting the propagation of the stress wave. Many research results have been made on the influence of non-continuous stress wave propagation in rock and soil mass and the dynamic response to seismic slopes. However, the effect of the continuity of the slip surface on the slope dynamic stability needs further researches. Therefore, in this paper, the effect of slip surface on the slope’s instantaneous safety factor is analyzed by the theoretical method with the infinite slope model. Firstly, three types of slip surface model were established, to realize the change of sliding surface continuity in the infinite slope. Then, based on wave field analysis, the instantaneous safety factor was used to analyze the effect of continuity of slip surface. The results show that with the decreasing of slip surface continuity, the safety factor does not simply increase or decrease, and is related to slope features, incident wave and continuity of slip surface. The safety factor does not decrease monotonically with the increasing of slope angle and thickness of slope body. Moreover, the reflection of slope surface has a great influence on the instantaneous safety factor of the slope. Research results in this paper can provide some references to evaluate the stability of seismic slope, and have an initial understanding of the influence of structural surface continuity on seismic slope engineering.

Influence of Structural Plane in Similar Soil Surrounding Rock on Excavation Stability

2010 ◽  
Vol 168-170 ◽  
pp. 1318-1324
Author(s):  
Qiang Chen ◽  
Wei Tao Chen ◽  
Guo Wei Meng
Keyword(s):  
Numerical Calculation ◽  
Surrounding Rock ◽  
Disintegration Time ◽  
Structural Plane ◽  
Research Results ◽  
Tunnel Stability ◽  
Excavation Stability ◽  
Shearing Strength ◽  
The Stability ◽  
Similar Soil

Lots of primary or secondary structural planes in similar soil surrounding rock are the main difference with Quaternary soil surrounding rock, but the particularity isn’t considered in the analysis of tunnel stability. The fact, which similar soil surrounding rock has most weak structural planes, is testified by engineering examples. The influence of structural plane in similar soil surrounding rock on excavation stability was analyzed through combining theory with disintegration test and numerical calculation. The research results show that there are a lot of structural planes in similar soil surrounding rock. The angle between structural planes and tunnel axes and shearing strength of structural planes control the stability of tunnel. Disintegration time of soil is shortened due to structural planes. On a certain condition, structural planes can induce local collapse in soil surrounding rock while excavating.

Analysis for the Stability of Irregular Wedge on Slope and its Engineering Application

2011 ◽  
Vol 94-96 ◽  
pp. 686-691
Author(s):  
Guan Rong ◽  
Bo Tao Zhang ◽  
Xiao Jiang Wang
Keyword(s):  
Safety Factor ◽  
Virtual Work ◽  
Engineering Application ◽  
Current Method ◽  
Left Bank ◽  
Calculation Results ◽  
Baihetan Hydropower Station ◽  
The Stability ◽  
Dissipation Equation ◽  
Improved Methods

Energy dissipation equation is obtained from the virtual work principle. By assuming different initiative sliding directions, methods of upper bound solution and classical solution for rock wedge stability are deduced. The computational formulas of safety factor indicate that the safety factor of wedge is depended on the areas of sliding surfaces and the volume of the wedge rather than the shape of the slope when the attitude and strength of discontinuities is given. Therefore the current wedge method can be improved to overcome the weakness that the current method is inapplicable when the slope shape is greatly rugged and the wedge is surrounded by more than three discontinuities. As an example, the improved method is applied in the left bank slope of Baihetan hydropower station. The calculation results obtained by the improved methods is more reasonable and credible.

Stability Analysis of the Nanjung Water Diversion Twin Tunnels based on Convergence Measurement

2019 ◽  
Vol 1 (1) ◽  
pp. 49-60
Author(s):  
Simon Heru Prassetyo ◽  
Ganda Marihot Simangunsong ◽  
Ridho Kresna Wattimena ◽  
Made Astawa Rai ◽  
Irwandy Arif ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Convergence Rate ◽  
Critical Strain ◽  
Convergence Rates ◽  
Strain Analysis ◽  
Water Diversion ◽  
Tunnel Face ◽  
Tunnel Stability ◽  
The Stability ◽  
Twin Tunnels

This paper focuses on the stability analysis of the Nanjung Water Diversion Twin Tunnels using convergence measurement. The Nanjung Tunnel is horseshoe-shaped in cross-section, 10.2 m x 9.2 m in dimension, and 230 m in length. The location of the tunnel is in Curug Jompong, Margaasih Subdistrict, Bandung. Convergence monitoring was done for 144 days between February 18 and July 11, 2019. The results of the convergence measurement were recorded and plotted into the curves of convergence vs. day and convergence vs. distance from tunnel face. From these plots, the continuity of the convergence and the convergence rate in the tunnel roof and wall were then analyzed. The convergence rates from each tunnel were also compared to empirical values to determine the level of tunnel stability. In general, the trend of convergence rate shows that the Nanjung Tunnel is stable without any indication of instability. Although there was a spike in the convergence rate at several STA in the measured span, that spike was not replicated by the convergence rate in the other measured spans and it was not continuous. The stability of the Nanjung Tunnel is also confirmed from the critical strain analysis, in which most of the STA measured have strain magnitudes located below the critical strain line and are less than 1%.

Slope Stability Analysis under the Condition of Seepage

2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin
Keyword(s):  
Finite Element Method ◽  
Shear Strength ◽  
Slope Stability ◽  
Negative Impact ◽  
Strength Reduction ◽  
Soil Slope ◽  
Failure State ◽  
Calculation Results ◽  
The Stability ◽  
Shear Strength Reduction

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.

Topology Optimization Design of High Pressure Storage Tank Structure

2012 ◽  
Vol 430-432 ◽  
pp. 828-833
Author(s):  
Qiu Sheng Ma ◽  
Yi Cai ◽  
Dong Xing Tian
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Topology Optimization ◽  
Storage Tank ◽  
Optimization Design ◽  
Influence Factors ◽  
Element Model ◽  
Design Variables ◽  
Calculation Results ◽  
Pressure Storage

In this paper, based on ANSYS the topology optimization design for high pressure storage tank was studied by the means of the finite element structural analysis and optimization. the finite element model for optimization design was established. The design variables influence factors and rules on the optimization results are summarized. according to the calculation results the optimal design result for tank is determined considering the manufacturing and processing. The calculation results show that the method is effective in optimization design and provide the basis to further design high pressure tank.

Redistribution of Internal Force under Structural Defect and Non-Linear Spatial Stability under Live Load and Wind of Tied-Arch Bridge

2013 ◽  
Vol 477-478 ◽  
pp. 640-645
Author(s):  
Qian Hui Pu ◽  
Hu Zhao
Keyword(s):  
Safety Factor ◽  
Mechanical Performance ◽  
Influence Factors ◽  
Internal Force ◽  
Structural Defects ◽  
Live Load ◽  
Positive Contribution ◽  
Arch Bridge ◽  
Initial Defect ◽  
Tied Arch Bridge

To study the mechanical performance and stability of tied-arch bridge under structural defects and damages, limited element modal of Panzhihua Luoguo Jinshajiang Bridge was established and analyzed. Firstly, some typical damage models and their influence factors were presented. Then, based on the model established, change of suspender force caused by arch rib lineation defect, hanger lineation defect and boom failure was calculated respectively. The stability safety factor under the load group composed of dead load, live load and wind was calculated as well as the second-class nonlinear stability safety factor under structural initial defect. Calculation results shows that, suspender forces were more sensitive to archs vertical defect than to transverse defect. While, short hangers were more sensitive to lineation defect than long ones, and secondary inner force in short booms were bigger than in long ones. The result also tells that lateral wind is bad to lateral stability. Lift wind, somehow, makes positive contribution to structures in-plane stability. Structural initial defect can draw down the second-class stability safety factor under geometric nonlinear condition.

Research on Predicting the Stability of Partially Stabilized Zirconia Based on SVM

2010 ◽  
Vol 146-147 ◽  
pp. 460-465 ◽  
Author(s):  
Sheng Hui Guo ◽  
Dong Bo Li ◽  
Li Jun Liu ◽  
Jin Hui Peng ◽  
Li Bo Zhang ◽  
...  
Keyword(s):  
Relative Error ◽  
Influence Factors ◽  
Commercial Application ◽  
Support Vector ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Typical Data ◽  
Svm Model ◽  
Commercial Process ◽  
The Stability

The stability is one most important product performance index, which can directly determine the quality of the partially stabilized zirconia (PSZ), and the stability of PSZ is always fluctuating in the commercial process, so how to accurately, quickly and easily predict the stability of PSZ in the preparation process is very important. In the present paper, a new mathematical model to predict the stability of PSZ was proposed, based on statistical theory (SLT) and support vector machine (SVM) theory, which relates the stability of PSZ and the influence factors, such as the holding temperature, rising rate of temperature, holding time, decreasing rate of temperature and hardening temperature. Typical data collected from commercial process were collected for the training samples and test samples. Then testing and analyzing was done. The results showed that the max relative error was 1.80%, the least relative error was 0%, and the average relative error was 0.58%. It is accurate and reliable to predict the stability of PSZ by SVM model. Besides, multiple influence factors can be comprehensively considered in the SVM model, thus a new highly effective method for predicting the stability of PSZ is provided for commercial application.

Some Relationship between Safety Factor of Earthquake Slope and Related Parameters

2011 ◽  
Vol 422 ◽  
pp. 688-692
Author(s):  
Xiao Hei He ◽  
Geng You Han ◽  
Rui Hua Xiao
Keyword(s):  
Numerical Simulation ◽  
Rock Mechanics ◽  
Safety Factor ◽  
Limit Equilibrium ◽  
Static Method ◽  
Acceleration Coefficient ◽  
The Wenchuan Earthquake ◽  
Stability Of Slope ◽  
The Stability ◽  
The Relationship

Abstract:Since the Wenchuan earthquake happened, the slope stability had been paid much more attention. The safety factor is an important parameter that can be used to evaluate the stability of slope. The pseudo-static method that based on limit equilibrium and the method of numerical simulation can calculate the safety factor accurately, but the velocity that gets the result is slow. If we can establish the relationship between safety factor and some other parameters, then we can calculate the safety factor by using the relationship more quickly. This paper establishes much relationship, such as the relationship between the rock mechanics parameters and the average danymic safety factor, the relationship between the rock mechanics parameters and the ratio of average danymic safety factor to static safety factor, the relationship between the rock mechanics parameters and the average earthquake acceleration coefficient, the relationship between the average earthquake acceleration coefficient and the ratio of average danymic safety factor to static safety factor, and the relationship between the earthquake acceleration coefficient and the ratio of danymic safety factor to static safety factor on the condition of different rock mass.

scholarly journals Numerical Analyses on the Stability of a Deep Coalmine Roadway Passing through a Fault Zone: A Case Study of the Gugui Coalfield in China

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2114
Author(s):  
Yongshui Kang ◽  
Congcong Hou ◽  
Jingyi Liu ◽  
Zhi Geng ◽  
Jianben Chen ◽  
...  
Keyword(s):  
Fault Zone ◽  
Distinct Element ◽  
Three Dimensional ◽  
Tectonic Stress ◽  
Three Dimensional Model ◽  
Support Strategy ◽  
Failure Theory ◽  
Calculation Results ◽  
Pass Through ◽  
The Stability

Massive deformation often occurs when deep coalmine roadways pass through a fault zone due to the poor integrity of rock mass and high tectonic stress. To study deformation characteristics of the surrounding rock in the fault zone of a coalmine, a roadway passing through the FD1041 fault zone in China’s Gugui coalfield was investigated in this research. The geo-stress characteristics of this fault zone were analyzed based on the Mohr failure theory. Furthermore, a three-dimensional model for the experimental roadway in the FD1041 fault zone was built and calculated by a numerical program based on the distinct element method. Stability conditions of the roadway, using several types of support methods, were calculated and compared. Calculation results indicated that pre-grouting provides favorable conditions for the stability of a roadway in a fault zone. Finally, an optimized support strategy was proposed and implemented in the experimental roadway. Monitored results demonstrated that the optimized support strategy is appropriate for this fault zone.

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