scholarly journals Blast Induced Damage to Surrounding Rock Mass in an Underground Excavation

Author(s):  
Harsh Kumar Verma ◽  
Narendra Kumar Samadhiya ◽  
Mahendra Singh ◽  
Vilugundam Venkat Ramana
Author(s):  
Van Min Nguyen ◽  
V. A. Eremenko ◽  
M. A. Sukhorukova ◽  
S. S. Shermatova

The article presents the studies into the secondary stress field formed in surrounding rock mass around underground excavations of different cross-sections and the variants of principal stresses at a mining depth greater than 1 km. The stress-strain analysis of surrounding rock mass around development headings was performed in Map3D environment. The obtained results of the quantitative analysis are currently used in adjustment of the model over the whole period of heading and support of operating mine openings. The estimates of the assumed parameters of excavations, as well as the calculations of micro-strains in surrounding rock mass by three scenarios are given. During heading in the test area in granite, dense fracturing and formation of tensile strain zone proceeds from the boundary of e ≥ 350me and is used to determine rough distances from the roof ( H roof) and sidewalls ( H side) of an underground excavation to the 3 boundary e = 350me (probable rock fracture zone). The modeling has determined the structure of secondary stress and strain fields in the conditions of heading operations at great depths.


2013 ◽  
Vol 405-408 ◽  
pp. 402-405 ◽  
Author(s):  
Yun Jie Zhang ◽  
Tao Xu ◽  
Qiang Xu ◽  
Lin Bu

Based on the fluid-solid coupling theory, we study the stability of surrounding rock mass around underground oil storage in Huangdao, Shandong province, analyze the stress of the surrounding rock mass around three chambers and the displacement change of several key monitoring points after excavation and evaluate the stability of surrounding rock mass using COMSOL Multiphysics software. Research results show that the stress at both sides of the straight wall of cavern increases, especially obvious stress concentration forms at the corners of the cavern, and the surrounding rock mass moves towards the cavern after excavation. The stress and displacement of the surrounding rock mass will increase accordingly after setting the water curtains, but the change does not have a substantive impact on the stability of surrounding rock mass.


2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang

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.


Author(s):  
Dan Huang ◽  
Xiao-Qing Li ◽  
Wen-Chao Song

In this study, grading of surrounding rock was based on rock mass basic quality (BQ) values according to the specifications in China. Numerical approach was to construct synthetic rock mass (SRM) model to represent the jointed rock mass, and obtain the strength of the rock mass. It represented intact rock by the bonded particle model (BPM), and represent joint behaviour by the smooth joint model (SJM) to construct the discrete fracture network (DFN). In the Hongtuzhang Tunnel, the micro properties of granite cores with different weathered degrees were determined by the validation process, and the calculation representative elementary volume (REV) of surrounding rock was 15 m×15 m. Five slightly weathered, three slightly to moderately weathered, and two moderately weathered granite surrounding rock mass models were established based on the probability distribution of joint sets in each borehole, the conversion BQ value was acquired according by the calculated strength of rock mass model. It was discussed the differences of surrounding rock grades between the geological survey method and the numerical calculation method, and then found that the geological survey report is higher than the numerical calculation method predicted. And the numerical calculation is consistent with the actual excavation of rock mass at borehole A1388.


2013 ◽  
Vol 838-841 ◽  
pp. 705-709
Author(s):  
Yun Hao Yang ◽  
Ren Kun Wang

Large scale underground caverns are under construction in high in-situ stress field at Houziyan hydropower station. To investigate deformation and damage of surrounding rock mass, a elastoplastic orthotropic damage model capable of describing induced orthotropic damage and post-peak behavior of hard rock is used, together with a effective approach accounting for the presence of weak planes. Then a displacement based back analysis was conducted by using the measured deformation data from extensometers. The computed displacements are in good agreement with the measured ones at most of measurement points, which confirm the validities of constitutive model and numerical simulation model. The result of simulation shows that damage of surrounding rock mass is mainly dominated by the high in-situ stress rather than the weak planes and heavy damage occur at the cavern shoulders and side walls.


2018 ◽  
Vol 175 ◽  
pp. 03025
Author(s):  
Feng Zhou ◽  
Hongjian Jiang ◽  
Xiaorui Wang

The problem about the stability of tunnel surrounding rock is always an important research object of geotechnical engineering, and the right or wrong of the result from stability analysis on surrounding rock is related to success or failure of an underground project. In order to study the deformation rules of weak surrounding rock along with lateral pressure coefficient and burying depth varying under high geostress and discuss the dynamic variation trend of surrounding rock, the paper based on the application of finite difference software of FLAC3D, which can describe large deformation character of rock mass, analog simulation analysis of surrounding rock typical section of the class II was proceeded. Some conclusions were drawn as follows: (1) when burying depth is invariable, the displacements of tunnel surrounding rock have a trend of increasing first and then decreasing along with increasing of lateral pressure coefficient. The floor heave is the most sensitive to change of lateral pressure coefficient. The horizontal convergence takes second place. The vault subsidence is feeblish to change of lateral pressure coefficient. (2) The displacements of tunnel surrounding rock have some extend increase along with increasing of burying depth. The research conclusions are very effective in analyzing the stability of surrounding rock of Yunling tunnel. These are going to be a reference to tunnel supporting design and construction.


Sign in / Sign up

Export Citation Format

Share Document