scholarly journals Study on reasonable grouting parameters based on UDEC numerical simulation

2019 ◽  
Vol 118 ◽  
pp. 02013
Author(s):  
Fengfeng Yang ◽  
Liping Bai ◽  
Ruiqing Su ◽  
Jufeng Zhang ◽  
Tai Xu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Field Test ◽  
Surrounding Rock ◽  
Frequent Occurrence ◽  
Roof Collapse ◽  
Grouting Reinforcement ◽  
Rock Roadway

In view of the frequent occurrence of roof collapse and chipping accidents in the broken surrounding rock roadway in the goaf, grouting reinforcement is applied to the surrounding rock of the ro ent ratio. The field test proves that the selected grouting parameters are reasonable and achieve the purpose of controlling the deformation of the surrounding rock of the roadway.

scholarly journals The Unsymmetrical Coefficient of Unsymmetrical-Loaded Tunnel Based on Field Monitoring and Numerical Simulation

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1793
Author(s):  
Tao Zhang ◽  
Lei Nie ◽  
Min Zhang ◽  
Shulin Dai ◽  
Yan Xu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Field Test ◽  
Slope Angle ◽  
Physical And Mechanical Properties ◽  
Surrounding Rock ◽  
Monitoring Point ◽  
Site Monitoring ◽  
Accurate Judgment ◽  
Overburden Thickness ◽  
Tunnel Design

We conducted a field test on Huitougou (HTG) Tunnel, which is a typical shallow-buried and unsymmetrically loaded tunnel. The on-site monitoring data indicated that the surrounding rock pressure and lining stress on both sides of the tunnel were indeed asymmetrical and that the pressure ratios (original unsymmetrical coefficient) of each corresponding monitoring point were different. According to the tunnel design principle, we proposed the unsymmetrical coefficient (UC) to characterize the asymmetrical degree of the tunnel, and verified and compared the UC of the field test and numerical simulation results. The effects of different factors on the UC such as the slope angle of the ground, the thickness of the overburden cover, the physical and mechanical properties of the surrounding rock, and the construction method were studied and analyzed. The research results reveal that the bias coefficient calculated by the numerical simulation was close to the monitoring results. The results of the factor analysis indicate that the slope angle, overburden thickness, and elastic modulus significantly affected the bias degree, while other factors had little effect. The concise and clear UC accurately described the unsymmetrical degree of any unsymmetrical-loaded tunnel and provided more accurate judgment regarding the safety of the tunnel design phase and construction phase.

scholarly journals Evolution of Interior and Exterior Bearing Structures of the Deep-Soft-Rock Roadway: From Theory to Field Test in the Pingdingshan Mining Area

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4357
Author(s):  
Qingxian Huang ◽  
Xufeng Wang ◽  
Xuyang Chen ◽  
Dongdong Qin ◽  
Zechao Chang
Keyword(s):  
Field Test ◽  
Soft Rock ◽  
Field Measurements ◽  
Mining Area ◽  
Surrounding Rock ◽  
Roadway Stability ◽  
Geological Conditions ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

Pingdingshan mining area is one of the typical deep mining areas in China, and most of the mines in this area are troubled by the difficulties of the deep-soft-rock roadway support. Based on the concept of synergistic interactions of the interior and exterior bearing structure of the surrounding rock and, considering the specific geological conditions of the research site, we establish the mechanical model of the interior and exterior bearing structure of the roadway. Based on numerical simulation, we reveal the influence of main factors, such as support strength and mechanical characteristics, of surrounding rock on the distribution and evolution of the interior and exterior bearing structure. We found that increasing the support strength and mechanical parameters of surrounding rock can make the exterior bearing structure close to the roadway enhance the bearing characteristics of the interior and exterior bearing structure and improve the roadway stability. The distribution characteristics of the interior and exterior bearing structure of the roadway under six different support strengths and six different grouting parameters were systematically investigated by field measurements. According to the field test results, an effective strategy for controlling the deep-soft-rock roadway is proposed, which provides a good reference for surrounding rock control of the deep-soft-rock roadway in the Pingdingshan mining area and mines with similar mining conditions.

The Study of Numerical Simulation about Roadway Bolting and Reinforcement to Jointed Rock Mass

2012 ◽  
Vol 577 ◽  
pp. 159-162 ◽  
Author(s):  
Zhi Qiang Kang ◽  
Shu Hui Yan ◽  
Qiu Yan
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Soft Rock ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Joint Surface ◽  
Shearing Resistance ◽  
Grouting Reinforcement ◽  
Soft Rock Roadway ◽  
Rock Roadway

Through the mechanical derivation on bolt grouting reinforcement shearing resistance strength of the joint surface, shows that bolt grouting reinforcement focus strengths on the anchor bolt and grouting, and it enhances and elaborates self-supporting ability of rock. Combined with the numerical simulation analysis using the Flac3D software during the jointing soft rock roadway with no supports and protections and bolt grouting reinforcement, we can see that bolt grouting reinforcement has a significant role on improving jointing soft rock roadway force status and limiting roadway rock deformation. Therefore bolt grouting reinforcement is a worthy technology to popularize.

Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Seam ◽  
Coal Mine ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Seam Mining

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

Numerical Simulation on the Effect of Compound Roof Separation Position on Bolting Performance

2014 ◽  
Vol 953-954 ◽  
pp. 1638-1642
Author(s):  
Ai Qing Liu ◽  
Jian Zhang ◽  
Peng Cheng ◽  
Yu Hai Zhang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Surrounding Rock ◽  
Cohesive Force ◽  
Roof Strata ◽  
Poor Stability ◽  
Key Parameter

Prestress is a key parameter in bolting, while the cohesive force of layers in the compound roof strata is low and prone to separation, causing the prestress proliferation very poor. With the method of numerical simulation analysis,the location of separation in compound roof to affect the performance of bolting support was researched. It is concluded the roof separation in the edge of anchorage zone, the prestress field superpose, but is away from the deep surrounding rock and shows poor stability,however the role of cable can make up for the defect of rockbolts support. It has been found the highly prestressed strength bolting system adapts to the compound roof.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

Characteristic Law of Borehole Deformation Induced by the Temperature Change in the Surrounding Rock of Deep Coalbed Methane Well

2021 ◽  
pp. 1-18
Author(s):  
Xin Li ◽  
Jie Zhang ◽  
Cuinan Li ◽  
Weilin Chen ◽  
Jingbin He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coalbed Methane ◽  
Linear Equations ◽  
Surrounding Rock ◽  
Experimental Temperature ◽  
Borehole Stability ◽  
Fracture Angle ◽  
High Deformation ◽  
Rock Temperature ◽  
Primary Fracture

Abstract The borehole stability of the coalbed methane (CBM) well has always been vital in deep CBM exploration and development. The borehole instability of the deep CBM well is due to many complicated reasons. The change in the surrounding rock temperature is an important and easily overlooked factor among many reasons. In this research, we used methods that include experiment and numerical simulation to study the characteristic law of the borehole deformation induced by the changes in the surrounding rock temperature of deep CBM well. The experimental results of the stress–strain curves of five sets of experiments show that when the experimental temperature rises from 40 °C to 100 °C, the average stress when coal samples are broken gradually decreases from 81.09 MPa to 72.71 MPa. The proportion of plastic deformation in the entire deformation stage gradually increases from 7.8% to 25.7%. Moreover, the characteristics that some key mechanical parameters of coal samples change with the experimental temperature are fitted, and results show that as the experimental temperature rises from 40 °C to 100 °C, the compressive strength, elastic modulus, and main crack length of coal samples show a gradually decreasing trend. By contrast, the Pois-son's ratio and primary fracture angle show a gradually increasing trend. Moreover, the relativity of the linear equations obtained by fitting is all close to 1, which can accurately reflect the corresponding change trend. Numerical simulation results show that a high temperature of the surrounding rock of the deep CBM well results in a high range of stress concentration on the coal seam borehole and high deformation.

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