Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel
The process of crack propagation and tunnel failure is affected by the cross-sectional geometry of an underground tunnel. In order to quantify the effect of section shape on the process of crack propagation in deep tunnels under high ground stress conditions, a total of four physical models with two...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2019-01-01
|
| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2019/3439543 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832564876238651392 |
|---|---|
| author | Xianjie Hao Shaohua Wang Duoxiang Jin Bo Ren Xiangyang Zhang Kailong Qiu Yingjie Fan |
| author_facet | Xianjie Hao Shaohua Wang Duoxiang Jin Bo Ren Xiangyang Zhang Kailong Qiu Yingjie Fan |
| author_sort | Xianjie Hao |
| collection | DOAJ |
| description | The process of crack propagation and tunnel failure is affected by the cross-sectional geometry of an underground tunnel. In order to quantify the effect of section shape on the process of crack propagation in deep tunnels under high ground stress conditions, a total of four physical models with two cross-sectional shapes and twelve stress levels were designed and several large-scale physical model tests were conducted. The results indicated that, when the vertical stress is 4.94 MPa, the length and depth of the cracks generated in the rock surrounding the horseshoe tunnel are about eight times that around a circular tunnel. The position where the circumferential displacement of the horseshoe tunnel begins to be stable is about two, to two and a half, times that around a circular tunnel. After the deep chamber was excavated, continuous spalling was found to occur at the foot of the horseshoe tunnel and microcracks in the surrounding rock were initially generated from the foot of the side wall and then developed upwards to form a conjugate sliding shape to the foot of the arch roof, where the cracks finally coalesced. Discontinuous spalling occurred at the midheight of the side wall of the circular tunnel after excavation, and microcracks in the surrounding rock were initially generated from the midheight of the side wall and then extended concentrically to greater depth in the rock mass surrounding the tunnel. Tensile failure mainly occurred on the surface of the side wall: shear failure mainly appeared in the surrounding rock. |
| format | Article |
| id | doaj-art-34a5044491f44dc5bfb7fee37a255117 |
| institution | Kabale University |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Civil Engineering |
| spelling | doaj-art-34a5044491f44dc5bfb7fee37a2551172025-02-03T01:09:54ZengWileyAdvances in Civil Engineering1687-80861687-80942019-01-01201910.1155/2019/34395433439543Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground TunnelXianjie Hao0Shaohua Wang1Duoxiang Jin2Bo Ren3Xiangyang Zhang4Kailong Qiu5Yingjie Fan6State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, ChinaSchool of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, ChinaSchool of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, ChinaSchool of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, ChinaCoal Mining National Engineering Technology Research Institute, Huainan 232000, ChinaSchool of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, ChinaSchool of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, ChinaThe process of crack propagation and tunnel failure is affected by the cross-sectional geometry of an underground tunnel. In order to quantify the effect of section shape on the process of crack propagation in deep tunnels under high ground stress conditions, a total of four physical models with two cross-sectional shapes and twelve stress levels were designed and several large-scale physical model tests were conducted. The results indicated that, when the vertical stress is 4.94 MPa, the length and depth of the cracks generated in the rock surrounding the horseshoe tunnel are about eight times that around a circular tunnel. The position where the circumferential displacement of the horseshoe tunnel begins to be stable is about two, to two and a half, times that around a circular tunnel. After the deep chamber was excavated, continuous spalling was found to occur at the foot of the horseshoe tunnel and microcracks in the surrounding rock were initially generated from the foot of the side wall and then developed upwards to form a conjugate sliding shape to the foot of the arch roof, where the cracks finally coalesced. Discontinuous spalling occurred at the midheight of the side wall of the circular tunnel after excavation, and microcracks in the surrounding rock were initially generated from the midheight of the side wall and then extended concentrically to greater depth in the rock mass surrounding the tunnel. Tensile failure mainly occurred on the surface of the side wall: shear failure mainly appeared in the surrounding rock.http://dx.doi.org/10.1155/2019/3439543 |
| spellingShingle | Xianjie Hao Shaohua Wang Duoxiang Jin Bo Ren Xiangyang Zhang Kailong Qiu Yingjie Fan Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel Advances in Civil Engineering |
| title | Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel |
| title_full | Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel |
| title_fullStr | Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel |
| title_full_unstemmed | Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel |
| title_short | Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel |
| title_sort | instability process of crack propagation and tunnel failure affected by cross sectional geometry of an underground tunnel |
| url | http://dx.doi.org/10.1155/2019/3439543 |
| work_keys_str_mv | AT xianjiehao instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel AT shaohuawang instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel AT duoxiangjin instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel AT boren instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel AT xiangyangzhang instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel AT kailongqiu instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel AT yingjiefan instabilityprocessofcrackpropagationandtunnelfailureaffectedbycrosssectionalgeometryofanundergroundtunnel |