scholarly journals Study on bearing capacity characteristics of steel structure support in soft rock roadway

2021 ◽  
Author(s):  
Ya‐bin Wu ◽  
Jian‐hua Hu ◽  
Xu‐yang Zhang ◽  
Ya‐guang Qin ◽  
Zhi‐bo Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soft Rock ◽  
Steel Structure ◽  
Soft Rock Roadway ◽  
Rock Roadway

Strength Assessments of Concrete-Filled Steel Tubular Support of Soft Rock Roadway

2013 ◽  
Vol 838-841 ◽  
pp. 1884-1890 ◽  
Author(s):  
Guang Long Qu ◽  
Yan Fa Gao ◽  
Liu Yang ◽  
Bin Jing Xu ◽  
Guo Lei Liu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Flexural Performance ◽  
Laboratory Test Results ◽  
Different Types ◽  
Soft Rock Roadway ◽  
Core Concrete ◽  
Rock Roadway

Compared with I-shaped and U-shaped supports in soft rock roadway, concrete-filled steel tubular (CFST) support, as a new supporting form, has stronger bearing capacity with reasonable price. So it is becoming more and more popular in roadway supporting of coal mine in China. In this article, the surrounding rock in soft rock roadway was classified into three different types: hard rock in deep coal mine, soft surrounding rock, extremely soft surrounding rock. And, according to the characteristics of deformation failure of the CFST support and the surrounding rock in the industrial tests, three different strength assessments, including assessment of axial compressive strength, assessment of lateral flexural performance, assessment of hardening rate of core concrete, were proposed through mechanical analysis and laboratory tests for the three different types of the surrounding rock, respectively. Moreover, aimed to insufficient flexural strength of the support or low hardening rate of the core concrete in some of the roadway supporting, strengthening lateral flexural performance or making early strength concrete was necessary for the above unfavorable situations. The laboratory test results showed that the ultimate bearing capacity for the CFST support with φ194*8mm of steel tube reinforced by φ38mm round steel was 31% greater than that of the unreinforced one, 177% greater than that of the U-shaped one with equivalent weight per unit length.

scholarly journals Deformation Mechanism and Support Technology of Deep and High-Stress Soft Rock Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Lujing Zheng ◽  
Yujun Zuo ◽  
Yafei Hu ◽  
Wei Wu
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
High Stress ◽  
Soft Rock ◽  
Physical And Mechanical Properties ◽  
Surrounding Rock ◽  
Rock Fragmentation ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In this study, the analysis and control of stability of surrounding rock in deep fractured soft rock roadway located in the underground mine of Jinfeng gold mine in Guizhou Province, China, has been investigated. The surrounding rock of roadway has been analyzed to characterize its deformation and failure mechanism through field survey, testing of rock physical and mechanical properties, in situ stress measure, analysis of mineral components of rock, and investigation of rock fragmentation degree. Based on the numerical simulation technology, the influence of different factors on the stability of roadway is studied. The physical and mechanical properties of surrounding rock and the bearing capacity of surrounding rock layer are to be improved to maintain the stability of broken soft rock roadway as high ground stress, rock fragmentation, and poor lithology leading to tunnel instability. Hence, a high-strength “cable bolt + fiber-reinforced shotcrete + steel mesh + split sets + resin bolt + cement grouting” combined support system has been proposed to improve the effective bearing structure significantly with high integrity and bearing capacity.

Experiment and Application Study on the Load-Bearing Properties of Shallow Arch Circular Concrete Filled Steel Tube Support

2014 ◽  
Vol 568-570 ◽  
pp. 1662-1666
Author(s):  
Jun Wang ◽  
Yan Fa Gao
Keyword(s):  
Bearing Capacity ◽  
Soft Rock ◽  
Steel Tube ◽  
Shallow Arch ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Filled Steel Tube ◽  
Theoretical Test ◽  
Soft Rock Roadway ◽  
Rock Roadway

Shallow arch circular concrete filled steel tube support has a good load-bearing capacity, which is used in soft rock roadway supporting to solve the problem of supporting instability and to reduce the amount of anti-invert excavation. In this paper, concrete filled steel tube supports of Φ168 ×6 are designed according to shallow arch circular concrete filled steel tube structures and their load-displacement curves, ultimate bearing capacity and support failure mode are especially tested in experiment. This shallow arch circular concrete filled steel tube support is also applied in very soft rock roadway supporting of No. 1 mine well of Chaganzhuoer in Xilinhot, Inner Mongolia and proved to be of good supporting effect. The shallow arch circular concrete filled steel tube support is of higher load-bearing capacity and of outstanding advantages in solving extremely soft rock roadway supporting problems, as is proved in both theoretical test and application.

scholarly journals Large Deformation Characteristics of Surrounding Rock and Support Technology of Shallow-Buried Soft Rock Roadway: A Case Study

2022 ◽  
Vol 12 (2) ◽  
pp. 687
Author(s):  
Liu Zhu ◽  
Qiangling Yao ◽  
Qiang Xu ◽  
Liqiang Yu ◽  
Qundi Qu
Keyword(s):  
Bearing Capacity ◽  
Soft Rock ◽  
Site Investigation ◽  
Surrounding Rock ◽  
Numerical Calculations ◽  
Deformation Characteristics ◽  
Damage Characteristics ◽  
Support Resistance ◽  
Soft Rock Roadway ◽  
Rock Roadway

The coal resources in the coal-rich area of western China are mostly located in the late diagenetic Cretaceous and Jurassic strata. In this paper, a study on the support of soft rock roadways was carried out in the background of the soft rock track roadway in the Jiebangou coal mine. The field investigation showed that the surrounding rocks of the roadway were weak, soft, and broken, and the surrounding rocks were cemented, with the roadway local deformation exceeding 1 m. The borehole television results showed that the surrounding rocks were mainly weak sandy mudstone and yellow mudstone. The average uniaxial compressive strength of the surrounding rock was 15.49 MPa. The roadway is a shallow buried soft rock roadway; site investigation revealed that the original U-shaped steel shed had an extremely low resistance to slip, the filling body behind the U-shaped steel shed fell off, the interaction between the U-shaped steel shed and the surrounding rock was poor, the U-shaped steel shed could not provide sufficient timely support resistance, and the bearing capacity of the U-shaped steel shed was far from consideration. The floor was not effectively supported. The floor had different degrees of the bottom drum, and frequent undercover caused new stress disturbances, which loosened the bottom corners of both rock types and made the shed legs move continuously inward, reducing the bearing capacity and actual support resistance of the bracket. Numerical calculations were performed to study the deformation characteristics of the surrounding rock of the tunnel and the yielding damage characteristics of the brace. The results showed that the current U-shack support strength was insufficient, the two sides were deformed by 950 mm, the bottom of the roadway bulged by 540 mm, and the surrounding rock was mainly shear damaged. The fall of the filler behind the shed caused damage to the U-shaped steel shed spire. Through site investigation results and numerical calculations, the deformation and damage characteristics of the soft rock roadway and its damage causes were analyzed, and the support technology system of ‘strengthening support for weak structural parts’ was proposed. This improved the mechanical properties of the weak structural support body, the stress state of the local surrounding rock, and the bearing capacity of the support structure, and effectively controlled the deformation, damage, and instability of the surrounding rock of the roadway, and deformation, damage, and destabilization of the roadway, thereby achieving overall stability for the surrounding rock of the roadway.

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.

High Strength Combined Support Technology in Deep High Stress Soft Rock Roadway

2012 ◽  
Vol 524-527 ◽  
pp. 598-603
Author(s):  
Nian Jie Ma ◽  
Zhi Qiang Zhao ◽  
Hua Zhao ◽  
Li Shuai Jiang
Keyword(s):  
High Stress ◽  
Soft Rock ◽  
High Strength ◽  
Parameter Determination ◽  
Test Results ◽  
Actual Measurement ◽  
Computer Numerical Simulation ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to solve the serious damage and repeat revision problem of high stress soft rock roadway in deep -950 level of Tangshan coal mine, based on the theory of the maximum stress level, together with the actual measurement of geostress and the laboratory mechanical parameters of rock-core and computer numerical simulation, the high strength combined support technology and supporting parameters are determined and the engineering test has been done. The engineering test results show that the parameter determination of high strength combined support technology, which based on the actual measurement of geostress, can effective solve the support issue of high stress soft rock roadway and provide useful experience for similar engineering problems.

Determination of loading capacity index of a continuous miner in soft rock roadway and virtual test method

2022 ◽  
pp. 095440622110616
Author(s):  
Hong Zhang ◽  
You Chen ◽  
Zhihong Zhang ◽  
Honghong Yan
Keyword(s):  
Energy Consumption ◽  
Soft Rock ◽  
Test Method ◽  
Energy Utilization ◽  
Loading Capacity ◽  
Continuous Miner ◽  
Loading Efficiency ◽  
Wheel Loading ◽  
Soft Rock Roadway ◽  
Rock Roadway

To improve the loading efficiency and reduce energy consumption of a continuous miner in soft rock roadway, a seven-arm star wheel designed with Gaussian fitting method was proposed, and a coal loading model of the continuous miner star wheel loading mechanism was reconstructed with EDEM software. The loading capacity of the seven-arm star wheel and the three-arm star wheel of the EML340 continuous miner at different working speeds were studied respectively. The scientific and reasonable identification index was formulated and the index evaluation system of loading star wheel was established. It has been found that the performance of the loading star wheel is a collection of various identification indicators, the coal returning mass reducing the loading efficiency and increasing unnecessary energy consumption, therefore, it is difficult to identify by a single index. Loading coal and rock by the star wheel is a process that consumes energy and pays attention to output, therefore, the identification index should include two kinds of efficiency parameters and energy parameters. Rake coal torque and loading specific energy consumption have reflected the degree of energy utilization, which can be comprehensively used for preliminary design of the star wheel. The performance parameters such as loading power and loading efficiency are reliable indicators for designing and performance evaluation of the star wheel. Based on the statistical analysis of the test data, compared with the three-arm star wheel of the EML340 continuous miner, the loading efficiency of the seven-arm star wheel has been significantly improved. The loading power for coal loading has been reduced by 46%. The feasibility of the Gaussian design method of loading star wheel has been verified.

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