The Application of ULRR-Rainfall Coupled in Forecast Prediction on Debris Landslide

2012 ◽  
Vol 446-449 ◽  
pp. 3023-3026
Author(s):  
Juan Zhang ◽  
Ke Qiang He ◽  
Shang Qing Wang ◽  
Wei Wang
Keyword(s):  
Water Environment ◽  
Dynamic Parameter ◽  
Response Ratio ◽  
Landslide Prediction ◽  
Systematic Analysis ◽  
Load Response ◽  
Debris Landslide ◽  
Geological Conditions ◽  
The Stability ◽  
Warning Model

According to the systematic analysis of the composition and destabilized mechanism of debris landslides, this paper have hydro-geological conditions of the landslide and rainfall combined, research the changes of Unload-load response ratio (ULRR), which is considered as the displacement dynamic parameter of debris landslide in the water environment of different roles and conditions. To further explore the stability and its instability law in different stages of the landslide, establish the ULRR-rainfall coupled warning model in order to improve the accuracy of landslide prediction greatly. Meanwhile, based on the example of Xintan, use the ULRR-rainfall coupled warning model to evaluate and predict its stability. The Evaluation and prediction results match the evolution of slope stability. All results above prove that the ULRR- rainfall coupled is a very effective and reliable new method in the forecast prediction of the debris 1andslide．

Theory of Unload-Load Response Ratio and its Application in Debris Landslide Forecast

2012 ◽  
Vol 166-169 ◽  
pp. 2735-2739
Author(s):  
Wei Gong Chen ◽  
Ke Qiang He ◽  
Juan Zhang
Keyword(s):  
Steady State ◽  
System Dynamics ◽  
Traditional Method ◽  
Load Parameter ◽  
Response Ratio ◽  
Deformation Stage ◽  
Response Parameter ◽  
Load Response ◽  
Debris Landslide

Debris landslide is a widely distributed and its hazard is huge and hard to forecast with traditional method. Instability drivers of the debris landslide and mechanism were systematically analyzed in this paper. And on that basis, the theory of unload-load response ratio was proposed to forecast the landslide's stability. In the view of system dynamics, the unload-load parameter and unload-load response parameter were singled out and the feasibility was able to build up analyzed, and then, the model of unload-load response ratio was built. As an example, the model was used to analyze and calculate the Xintan typical debris landslide. The results were showed. The steady state reflected by the timing curve of the unload-load response ratio was consistent with the landslide's actual status, when Y'→0, the overall unstability of landslide would appear. That showed it was available to use the unload-load response ratio to forecast landslide's deformation stage and as a criterion of landslide instability.

A New Dynamic Prediction Method and its Application in Prediction of the Colluvial Landslides Induced by Rainfall

2012 ◽  
Vol 170-173 ◽  
pp. 3-7
Author(s):  
Ke Qiang He ◽  
Qiang Gang Yan ◽  
Wei Gong Chen ◽  
Min Zhao
Keyword(s):  
Prediction Method ◽  
Dynamic Parameter ◽  
Response Ratio ◽  
Dynamic Prediction ◽  
Case Study Analysis ◽  
Stability Of Slopes ◽  
Dynamic Factors ◽  
Xintan Landslide ◽  
The Stability

A lot of data indicates that rainfall has always played the very important role in landslide triggering. The paper discusses rainfall as a dynamic parameter in term of the load/unload response ratio theory, using the Xintan landslide as a case study. Analysis of the available data indicates that the occurrences of landslides in this region are controlled by rainfall, whose intensity and rainfall processes are the most important dynamic factors in determining the stability of slopes. Therefore, the relationship between rainfall and the movement of typical landslides has been specifically analyzed for the Xintan landslides by using the loading/unloading response ratio parameter of rainfall. The result of this study indicates that the mutation of the loading/unloading response ratio of rainfall of the Xintan landslide in the Three Gorges Reservoir regions, China occurred just before their destabilization, which shows that the loading/unloading response ratio of rainfall and its changing feature can be taken as a precursor for the landslides induced by rainfall.

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.

Study on Water Environmental Integrated Management Modeling Platform in Zhangweinan Basin, China

2013 ◽  
Vol 726-731 ◽  
pp. 3506-3512 ◽  
Author(s):  
Shu Yuan Li ◽  
Jian Hua Tao ◽  
Lei Yu
Keyword(s):  
Bohai Sea ◽  
Integrated Management ◽  
Water Environment ◽  
Pollutant Load ◽  
The Bohai Sea ◽  
Management Platform ◽  
Platform Architecture ◽  
And Control ◽  
Warning Model ◽  
Resource Shortage

Zhangweinan basin is a typical area where has the most serious water resource shortage and water environmental deterioration problems in north of China. To improve the increasingly deteriorated water eco-environment, studies on the integrated management of water resources and water environment in the basin were carried out with focus on the prevention and control of water pollution, and based on which, an integrated management platform on water environment was developed. This paper introduces the platform architecture and elaborates the construction process of the total pollutant load control model and pollution incident early warning model. This platform provides technical supports for weakening the total pollutant load in the basin, reducing the pollutant load flowing into the Bohai Sea, and increasing the eco-flow of river channel and flow into the Bohai Sea.

scholarly journals Numerical Modelling of The Behavior of Tunnel in Soft Surrounding Rock. A Case Study of Djebel El-Ouahch Tunnel, Algeria.

2021 ◽  
Author(s):  
Barkane Aicha ◽  
Sami Mezhoud
Keyword(s):  
Reference Model ◽  
Soil Behavior ◽  
Tunnel Excavation ◽  
Circular Section ◽  
Geological Conditions ◽  
The Stability ◽  
Tunnel Cross Section ◽  
Calculation Code ◽  
Surrounding Soil

Abstract The response of a massif to stresses generated by tunnel excavation depends essentially on the geological conditions, the geometry of the tunnel and its underground position. The major problem related to the construction of these structures is to ensure the stability of the whole tunnel-ground, by controlling the various deformation generated during the constructionIn this context, the present paper examines the effect of these conditions on the behavior of tunnels and the surrounding soil. The study is applied to a real tunnel, in this case the tunnel of Djebel El Ouahch, Algeria was taken as a reference model. The research includes a parametric study to evaluate the effect of several parameters on the behavior of the tunnel and surrounding soil such as the tunnel anchoring depth, the tunnel-soil interface rate, and the shape of the tunnel cross section. The analysis is performed using the PLAXIS 3D TUNNEL calculation code with an elastoplastic Mohr-coulomb model for the soil behavior. The results show that the strongest and most stable position is the mid-deep tunnel with a circular section, with a non-slip interface between the tunnel and the ground. These outcomes can help to understand the effects of various influences parameters which control the stability of the tunnel in a soil with bad characteristics.

scholarly journals Study on the Influence of Mud Properties on the Stability of Excavated Face of Slurry Shield and the Quality of Filter Cake Formation

2020 ◽  
Vol 8 (4) ◽  
pp. 291
Author(s):  
Hu Wang ◽  
Jian Chen ◽  
Hongjun Liu ◽  
Lei Guo ◽  
Yao Lu ◽  
...  
Keyword(s):  
Filter Cake ◽  
Volume Ratio ◽  
Vertical Displacement ◽  
Support Pressure ◽  
Longitudinal Displacement ◽  
Growth Trend ◽  
Cake Formation ◽  
Geological Conditions ◽  
The Stability

In the construction of subsea tunnels, the stability and control of the excavation surface are the main concerns of the engineering community. In this paper, the Xiamen Metro Line 2 is used as the study case. The filter cake formation of mud shields is experimentally studied, and the excavation surface is numerically simulated. It is found that the formation of filter cake does not require a large pressure difference, and can be formed under 0.06 MPa. With the increase of pressure, the quality of filter cake is further improved, and a small amount of seawater (volume ratio less than 3%) also has a significant effect on the viscosity of mud. Under different cross-section geological conditions, with the decrease of the support pressure of the excavation face, the vertical displacement and vertical (Y-direction) displacement of the excavation face dome gradually increase, the maximum longitudinal displacement is 9.7 mm, the maximum longitudinal displacement can reach 23.9 mm, and the growth trend is nonlinear. According to different stratum conditions, during the excavation of the tunnel, the plastic area of the excavation face is different.

scholarly journals Evolution Laws of Mining-induced Stress in Floor Strata and Its Influence on the Stability of a Floor Roadway Affected by Overhead Mining

2020 ◽  
Vol 24 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Pu Wang ◽  
Lishuai Jiang ◽  
Changqing Ma ◽  
Anying Yuan
Keyword(s):  
Numerical Simulation ◽  
Mechanical Model ◽  
Scientific Basis ◽  
Pull Out ◽  
Induced Stress ◽  
Working Face ◽  
Geological Conditions ◽  
Evolution Laws ◽  
The Stability

The study of evolution laws of the mining-induced stress in floor strata affected by overhead mining is extremely important with respect to the stability and support of a floor roadway. Based on the geological conditions of the drainage roadway in the 10th district in a coalmine, a mechanical model of a working face for overhead mining over the roadway is established, and the laws influencing mining stress on the roadway in different layers are obtained. The evolution of mining stress in floor with different horizontal distances between the working face and the floor roadway that is defined as LD are examined by utilizing UDEC numerical simulation, and the stability of roadway is analyzed. The results of the numerical simulation are verified via on-site tests of the deformation of the surrounding rocks and bolts pull-out from the drainage roadway. The results indicate that the mining stress in floor is high, which decreases slowly within a depth of less than 40 m where the floor roadway is significantly affected. The mining stress in the floor increases gradually, and the effect of the mining on the roadway is particularly evident within 0 m ≤ LD ≤ 40 m. Although the floor roadway is in a stress-relaxed state, the worst stability of the surrounding rocks is observed during the range -20 m ≤ LD < 0 m, in which the negative value indicates that the working face has passed the roadway. The roadway is affected by the recovery of the abutment stress in the goaf when -60 m ≤ LD <20 m, and thus it is important to focus on the strengthening support. The results may provide a scientific basis for establishing a reasonable location and support of roadways under similar conditions.

Mechanics Analysis of Grade V Surrounding Rock Primary Support in Maanziliang Tunnel

2012 ◽  
Vol 164 ◽  
pp. 414-417
Author(s):  
Jia Ming Han
Keyword(s):  
Finite Element ◽  
Safety Factor ◽  
Surrounding Rock ◽  
Qinling Mountains ◽  
The Finite Element Method ◽  
Highway Tunnel ◽  
Geological Conditions ◽  
The Stability ◽  
Primary Support ◽  
Rock Section

Commonly used finite element strength reduction to calculate the safety factor of slope，to analyze the stability of the slope[1～3]. Recently it also proposed the methods to evaluate the safety factor for the stability of surrounding rock of underground chambers and supporting structural mechanics[4～6]. For Qinling Mountains of the complex geological conditions in the Maanziliang highway tunnel, this article use the finite element method from the bolt resist tension, bolt length, the force of sprayed layer of concrete to computing gradeⅤsurrounding rock section of primary support safety factor, to give evaluation to support mechanics of the Maanziliang tunnel.

The Monitoring and Numerical Simulation Analysis on the Construction of a Shallow Underpass

2014 ◽  
Vol 580-583 ◽  
pp. 1056-1060
Author(s):  
Li Sheng Liu ◽  
Jie Zhao
Keyword(s):  
Simulation Analysis ◽  
Dynamic Monitoring ◽  
Ground Settlement ◽  
Control Effect ◽  
Influence Curves ◽  
Geological Conditions ◽  
Vertical Ground ◽  
The Stability ◽  
Underground Passage ◽  
Strain Model

Based on the dynamic monitoring project of one underpass in Dalian, this paper tries to validate the control effect of the ground settlement on the stability of tunnel surrounding rocks during construction of underground passage under urban arterial road by means of analyzing the vertical ground settlement curves, convergence curves of tunnel inner perimeter and vault displacement curves. With the numerical calculation tool of the software FLAC, it also analyzes the construction of XS-2 # cross-section which was in the south side of the whole construction section at different stages by adopting the plane-strain model. Therefore, we can get the influence curves of ground settlement under different construction stages with considering the release of stress. The simulation results are basically consistent with the measured data, which has a great significance for the subsequent design and construction of underground projects with similar geological conditions.

scholarly journals The Stability of Gob-Side Entry Retaining in a High-Gas-Risk Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Junwen Zhang ◽  
Yulin Li
Keyword(s):  
Coal Mines ◽  
Surrounding Rock ◽  
Shanxi Province ◽  
Engineering Practice ◽  
Efficient Production ◽  
Coal Recovery ◽  
Working Face ◽  
Geological Conditions ◽  
The Stability ◽  
Strengthening Technique

There are series of problems faced by most of the coal mines in China, ranging from low-coal recovery rate and strained replacement of working faces to gas accumulation in the upper corner of coalfaces. Based on the gob-side entry retaining at the No. 18205 working face in a coal mine in Shanxi Province, theoretical analysis, numerical simulation, and engineering practice were comprehensively used to study the mechanical characteristics of the influence of the width of the filling body beside the roadway and the stability of surrounding rock in a high-gas-risk mine. The rational width of the filling body beside the roadway was determined, and a concrete roadway-side support with a headed reinforcement-integrated strengthening technique was proposed, which have been applied in engineering practice. The stability of the filling body beside the roadway is mainly influenced by the movement of the overlying rock strata, and the stability of the surrounding rock can be improved effectively by rationally determining the width of the filling body beside the roadway. When the width of the roadway-side filling body is 2.5 m, the surrounding rock convergence of the gob-side entry retaining is relatively small at only 5% of the convergence ratio. It has been shown that the figure for roof separation is relatively low, and strata behaviors are relatively alleviated and gas density do not exceed the limit, which are the best results of gob-side entry retaining. The results of this research can provide theoretical guidance for excavation of coal mines with similar geological conditions and have some referential significance to safety and efficient production in coal mines.

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