scholarly journals Study on the Applicability of an Improved Pile-Beam-Arch Method of Metro Station Construction in the Upper-Soft and Lower-Hard Stratum

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xinping Guo ◽  
Annan Jiang ◽  
Shanyong Wang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Great Influence ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Vertical Stress ◽  
Surface Settlement ◽  
Metro Station ◽  
Study Laboratory ◽  
The Impact

The main challenge for metro station construction is to ensure the construction schedule while minimizing the impact on the surrounding environment. Based on the characteristics of the upper-soft and lower-hard stratum in the Dalian city of China, a special structure with six pilot tunnels and three spans of the pile-beam-arch (PBA) method is proposed and applied to the construction of the Labor Park metro station. In this study, laboratory experiments, numerical simulation analysis, and field monitoring data are used to investigate the applicability of six pilot tunnels and three spans of the PBA method in the process of construction. In the process of numerical simulation, the ground surface settlement, arch vertical displacement, the horizontal displacement of rock mass on both sides of the station, and vertical stress of support structure are analyzed. The numerical simulation results are found to be in good agreement with field measurement. Furthermore, the results indicate that, in the construction of six pilot tunnels and three spans of the PBA method, pilot tunnel construction and arch construction have a great influence on the surface settlement. The part of the initial vertical support of the pilot tunnels is removed, which caused the change of the position of maximum vertical stress and the redistribution of vertical stress. Because of reinforcement by side piles on both sides of the station, the horizontal displacement of the rock mass was reduced by 44.76% compared with that without reinforcement. The six pilot tunnels and three spans of the PBA method can effectively control the surface settlement, arch vertical displacement, and horizontal displacement of the rock mass.

Prestressed Anchor Bolt Impact on the Deformation of Composite Soil Nailing

2013 ◽  
Vol 353-356 ◽  
pp. 11-15
Author(s):  
Deng Qun Wang ◽  
Yan Peng Zhu
Keyword(s):  
Axial Force ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Soil Nailing ◽  
Foundation Pit ◽  
Obvious Effect ◽  
Anchor Bolt ◽  
Soil Nail ◽  
Finite Element Software ◽  
The Impact

Finite element software was employed to establish a model to simulate the compound soil nailing. The model simulates the process of constructing prestressed compound soil nailing. Compared the condition prestressed with no prestress, analyzed the Impact of prestress anchor on the deformation in the process of construction and the effect on axial force of soil nail. Applying prestress is able to control the horizontal displacement obviously, but has not obvious effect on vertical displacement, especially place the anchor bolt at the lower part of the slope. In the process of construction, prestress has an advance effect on the deformation of foundation pit and the axial force of soil nails near the anchor bolt.

Numerical Analysis of Deformation of Foundation in the Process of Constructing Soil Dam

2014 ◽  
Vol 962-965 ◽  
pp. 2939-2943
Author(s):  
Hai Jian Sun ◽  
Yong Quan Li
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Numerical Method ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Engineering Practice ◽  
Consolidation Process

Matching Mohr-Coulomb parameters to the Drucker-Prager model is deduced and the method of transferring to equivalent sand wall in drain pile ground is introduced in detail. Numerical simulation is conducted in the process of constructing soil dam. The results show that the maximum vertical displacement happens in the center of the dam and the maximum horizontal displacement happens in the toe of the dam. The numerical method in this paper may be used to predict the consolidation process in drain pile ground in the process of constructing soil dam. Those results gained by numerical method may provide reference to engineering practice.

scholarly journals Determination of Reasonable Width of Filling Body for Gob-Side Entry Retaining in Mining Face With Large Cutting Height

2021 ◽  
Author(s):  
Shijiang Pu ◽  
Gui yi Wu ◽  
Qinzhi Liu ◽  
Yuliang Wang ◽  
Qiang Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mechanical Model ◽  
Vertical Displacement ◽  
Vertical Stress ◽  
Body Width ◽  
Minimum Width ◽  
Mining Face ◽  
The Stability ◽  
Cutting Height ◽  
Two Sides

Abstract When gob-side entry retaining is adopted in mining face with large cutting height, due to large stope space, strong dynamic pressure and other reasons, the filling body is usually broken and unstable due to improper width of filling body, and the stability of surrounding rock of roadway is poor. Therefore, this paper will take Shaqu mine as the engineering background to study the reasonable filling body width of gob-side entry retaining in mining face with large cutting height. Firstly, the stability factors of gob-side entry retaining in mining face with large cutting height are analyzed, and the mechanical model of bearing structure of gob-side entry retaining is established based on the lateral pressure and overlying load of filling body, and the reasonable width of filling body is obtained quantitatively; Numerical simulation is used to analyze the evolution of vertical stress, vertical displacement and plastic zone of working face with the change of filling body width. Finally, combined with the deformation observation results of 24207 gob-side entry retaining roof, two sides and filling body, the rationality of filling body width is verified. The results show that: the setting of the width and strength of the filling body plays an important role in the stability of gob-side entry retaining. According to the mechanical model, the minimum width of the filling body is 2.2m in the lateral direction and 3.9m in the vertical direction; Numerical simulation shows that when the width of filling body is too small, with the increase of filling body width, the vertical stress of filling body increases gradually. When the width of filling body reaches a certain value, the vertical stress decreases with the increase of width, and the stress concentration area will change from symmetrical type to eccentric load type, from the middle of filling body to the side of filling body near gob. If the width of the filling body is too small, the filling body will be too broken to bear the load, resulting in too small vertical stress and too large vertical displacement of the roadway roof. The larger the width of the filling body is, the greater the cutting resistance is, the more timely the side roof of the gob can be cut off, the less the stress of the roadway and the filling body, and the more stable the retained roadway is. Finally, through the observation of 24207 gob-side entry retaining, the total deformation of two sides and roof and floor of roadway tends to be stable after 665mm and 597mm respectively. The roof of roadway does not appear severe subsidence and obvious cracking, and the floor does not appear too large floor heave. The effect of roadway retaining is good, which indicates that 4m support can meet the needs of practical engineering.

scholarly journals Evaluation of a Tunnel Underpass Building Scheme in Yunnan Province

2019 ◽  
Vol 136 ◽  
pp. 04019
Author(s):  
Xiwen Yang ◽  
Tiefeng Zhou ◽  
Xiangyang Cui ◽  
Hongyan Guo ◽  
Ke Li
Keyword(s):  
Structural Damage ◽  
Yunnan Province ◽  
Residential Buildings ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
The Impact

Side-crossing residential buildings in tunnel construction may lead to building subsidence, structural damage by tension and affect the use of buildings. Aiming at the structural damage caused by the side-crossing structure of Re Shuitang Tunnel NO.1, by simulating the influence of tunnel construction on the building, it is concluded that the surrounding rock above the tunnel will be deformed when the tunnel crosses the building. The maximum horizontal displacement is 0.64 mm and the maximum vertical displacement is 4.43 mm. According to the analysis results, the surrounding rock above the tunnel should be strengthened in time, and attention should be paid to the impact of blasting on residential buildings, so as to ensure the safety of buildings and provide reference for future construction.

Finite Element Numerical Simulation Analysis on Deformation of Adjacent Building with Shallow Foundation due to Excavation

2013 ◽  
Vol 353-356 ◽  
pp. 403-406
Author(s):  
Yong Kang Yang ◽  
Xiao Yuan Li ◽  
Wu Yang ◽  
Chun Yan Feng
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Simulation Analysis ◽  
Horizontal Displacement ◽  
Element Model ◽  
Vertical Displacement ◽  
Shallow Foundation ◽  
Foundation Pit ◽  
Adjacent Building ◽  
Finite Element Numerical Simulation

Based on deformation of adjacent building with shallow foundation of foundation pit excavation, Midas GTS is adopted to establish the finite element model. Through the numerical simulation, the maximum horizontal and vertical displacement in different conditions, Influence of different SMW pile stiffness and influence of different anchor position are analyzed. The results show that (1) horizontal deformation of SMW pile is decreased at the anchor construction; (2) compared with maximum horizontal displacement of SMW pile with 25a25b28a, the maximum horizontal displacement of SMW pile with 28b is increased by 50.9, 43.3, 11.5% respectively; (3) compared with the second anchor at 1.5, 3.5m, the horizontal displacement of adjacent building is minimal by the second anchor at 2.5m.

scholarly journals Numerical Simulation of Rock Mass Structure Effect on Tunnel Smooth Blasting Quality: A Case Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10761
Author(s):  
Jianxiu Wang ◽  
Ansheng Cao ◽  
Jiaxing Liu ◽  
Huanran Wang ◽  
Xiaotian Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Layered Structure ◽  
High Speed ◽  
Numerical Test ◽  
Great Influence ◽  
Structure Effect ◽  
Rock Mass Structure ◽  
Massive Structure ◽  
Smooth Blasting

Taking the Zigaojian tunnel, Hangzhou–Huangshan high-speed railway, China, as background, the rock mass structure effect on smooth blasting quality was studied. Four rock mass structures were determined on the basis of the information collected on the tunnel site. Smooth blasting finite element models were established using LS-DYNA. The accuracy of the numerical calculation model was verified by comparing the overbreak and underbreak between the numerical simulation and monitoring. Orthogonal numerical test was used to study the rock mass structure effect through single factor and main effect analysis methods. With the decrease in rock mass integrity, the smooth blasting overbreak of tunnels with massive integrity structure, massive structure, layered structure, and cataclastic structure increased. For massive integrity structure and cataclastic structure, the peripheral hole spacing should be emphatically considered. Meanwhile, in massive structure and layered structure, the included angle and spacing of structural planes had a great influence on the smooth blasting quality. The research results could provide a reference to improve the quality of similar tunnel smooth blasting.

Numerical Simulation Research for Stress and Distortion of Pile-Anchor Support Structure of the Deep Foundation

2011 ◽  
Vol 243-249 ◽  
pp. 3128-3131 ◽  
Author(s):  
Bang Jia Liu ◽  
Qian Xu
Keyword(s):  
Numerical Simulation ◽  
Great Influence ◽  
Horizontal Displacement ◽  
Parameter Change ◽  
Deep Foundation ◽  
Support Structure ◽  
Simulation Research ◽  
Shenyang City ◽  
Deep Foundation Excavation ◽  
Vertical Spacing

This article has used the ADINA numerical calculus software to simulate the deep foundation excavation and supports process, as well as analyzing the analogue result in the project of the Xia Gong in ShenYang City. The results illustrate that (1) it is essential to optimize the pile earth's horizontal displacement and the mechanical situation of anchor rod. (2) It makes soil’s horizontal displacement and the mechanical situation of anchor rod more reasonable by changing the anchor rod vertical spacing and length ，hence obtains that the anchor parameter change has the great influence on the distortion of the support structure.

scholarly journals The Impact of Multiple Seam Mining Exploitations on Seismic Activity and State of Stress

2017 ◽  
Vol 39 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Tadeusz Majcherczyk ◽  
Zbigniew Niedbalski
Keyword(s):  
Rock Mass ◽  
Seismic Activity ◽  
Vertical Stress ◽  
Hard Coal ◽  
Variable Degree ◽  
Concentration Coefficient ◽  
A Value ◽  
State Of Stress ◽  
Seam Mining ◽  
The Impact

Abstract The paper presents an analysis of seismic activity for selected areas of hard coal mine executing exploitation in a rock mass with a variable degree of rock disturbance, i.e., also with a varied number of previous mined-out seams. A distribution of vertical stress and a value of vertical stress concentration coefficient were also determined in the strata of immediate roof of the seams planned for mining. In the analyzed case, despite the lack of thick and solid strata of sandstones in the roof, the rock mass emits seismic activity, where the energy largely depends upon an impact of exploitation edges and tectonic disturbance.

scholarly journals Numerical and Similarity Simulation Study on the Protection Effect of Composite Protective Layer Mining with Gently Inclined Thick Coal Seam

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jianhong Ma ◽  
Chao Hou ◽  
Jiangtao Hou
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Simulation Analysis ◽  
Protective Layer ◽  
Vertical Displacement ◽  
Vertical Stress ◽  
Distribution Law ◽  
Gas Drainage ◽  
Thick Coal Seam ◽  
Maximum Expansion

Protective layer mining, as a dominating method for preventing coal and gas outburst, is generally adopted in highly gassy coal mines. In the absence of a suitable thickness coal seam to serve as the protective layer, the rock-coal composite protective layer was proposed in this paper. We conducted a series of simulations and engineering measurements to investigate the protective effect under the mining of the rock-coal composite protective layer of the Zhongtai coal mine located in the Hebi area of Henan, China. The numerical simulation analysis showed that, after the completion of protective layer mining, the minimum vertical stress of the No. 2-1 coal seam had been reduced to 3.46 MPa. The maximum vertical displacement of the No. 2-1 coal seam is 455.01 mm. The maximum expansion deformation of the No. 2-1 coal seam is 9.77‰; the effective pressure relief range is as long as 160 m. The similarity simulation experiment revealed that, after the completion of protective layer mining, the minimum vertical stress of the No. 2-1 coal seam is 4.0 MPa. The maximum vertical displacement of the No. 2-1 coal seam is 640 mm. The maximum expansion deformation of the No. 2-1 coal seam is 26.37‰; the effective protection range reaches 130 m. The engineering measurements demonstrated that the variation law of gas drainage parameters in the protected layer corresponds to the protected layer's vertical stress distribution law in numerical simulation and similarity simulation. With the exploitation of the composite protective layer, the protective layer’s pressure begins to release. The average gas drainage concentration is 2-3 times of that before the composite protective layer mining.

Sign in / Sign up

Export Citation Format

Share Document