Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method
Excavation damaged zones (EDZs) in deeply buried underground powerhouse have become major obstacles to design and support, which potentially threaten safety and stability and increase construction and support costs. In this study, investigations of the EDZs were performed by applying an acoustic vel...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2020-01-01
|
| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2020/7297260 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832547634382897152 |
|---|---|
| author | Liguo Zhang Dong Wang Jiaxing Dong |
| author_facet | Liguo Zhang Dong Wang Jiaxing Dong |
| author_sort | Liguo Zhang |
| collection | DOAJ |
| description | Excavation damaged zones (EDZs) in deeply buried underground powerhouse have become major obstacles to design and support, which potentially threaten safety and stability and increase construction and support costs. In this study, investigations of the EDZs were performed by applying an acoustic velocity detecting method in Houziyan hydropower project, southwest of China. A total of 38 testing boreholes distributed in high sidewalls of the main powerhouse were carried out, and corresponding 153 curves were obtained and analyzed. Then, EDZs were divided into highly damaged zone (HDZ), slightly damaged zone (SDZ), and excavation influence zone (EIZ), respectively. Furthermore, we classified the wave velocity curves into four categories: type I, type II, type III, and type IV. EDZs were qualitatively assessed based on the curve categories; in addition, we used a qualitative assessment method, which mainly involved an index of damage degree named D. The assessment results show that HDZ, but not SDZ, was significantly asymmetrically distributed in the upstream (average depth of 4.1 m) and downstream (average depth of 7.5 m) high sidewalls; in partial areas, depth of HDZ exceeded the length of designed rock bolts, which indicates that rock bolts cannot restrain crack development and EDZs evolution. Generally, EDZs distribution was consistent with deformation and failure phenomena distribution; compared to the field failure phenomena, the assessment results were reliable and reasonable. Finally, EDZs formation mechanism was discussed, and it can be concluded that the relatively large intermediate principal stresses σ2 were a critical driving factor of the EDZs evolution. |
| format | Article |
| id | doaj-art-533ea0c2f2a549f48c816c1e270195b2 |
| institution | Kabale University |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Civil Engineering |
| spelling | doaj-art-533ea0c2f2a549f48c816c1e270195b22025-02-03T06:44:00ZengWileyAdvances in Civil Engineering1687-80861687-80942020-01-01202010.1155/2020/72972607297260Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting MethodLiguo Zhang0Dong Wang1Jiaxing Dong2College of Mining, Liaoning Technical University, Fuxin, Liaoning 125105, ChinaCollege of Mining, Liaoning Technical University, Fuxin, Liaoning 125105, ChinaFaculty of Electric Power Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, ChinaExcavation damaged zones (EDZs) in deeply buried underground powerhouse have become major obstacles to design and support, which potentially threaten safety and stability and increase construction and support costs. In this study, investigations of the EDZs were performed by applying an acoustic velocity detecting method in Houziyan hydropower project, southwest of China. A total of 38 testing boreholes distributed in high sidewalls of the main powerhouse were carried out, and corresponding 153 curves were obtained and analyzed. Then, EDZs were divided into highly damaged zone (HDZ), slightly damaged zone (SDZ), and excavation influence zone (EIZ), respectively. Furthermore, we classified the wave velocity curves into four categories: type I, type II, type III, and type IV. EDZs were qualitatively assessed based on the curve categories; in addition, we used a qualitative assessment method, which mainly involved an index of damage degree named D. The assessment results show that HDZ, but not SDZ, was significantly asymmetrically distributed in the upstream (average depth of 4.1 m) and downstream (average depth of 7.5 m) high sidewalls; in partial areas, depth of HDZ exceeded the length of designed rock bolts, which indicates that rock bolts cannot restrain crack development and EDZs evolution. Generally, EDZs distribution was consistent with deformation and failure phenomena distribution; compared to the field failure phenomena, the assessment results were reliable and reasonable. Finally, EDZs formation mechanism was discussed, and it can be concluded that the relatively large intermediate principal stresses σ2 were a critical driving factor of the EDZs evolution.http://dx.doi.org/10.1155/2020/7297260 |
| spellingShingle | Liguo Zhang Dong Wang Jiaxing Dong Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method Advances in Civil Engineering |
| title | Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method |
| title_full | Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method |
| title_fullStr | Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method |
| title_full_unstemmed | Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method |
| title_short | Assessment of the Excavation Damaged Zones in the Surrounding Rock of an Underground Powerhouse under High In Situ Stress Using an Acoustic Velocity Detecting Method |
| title_sort | assessment of the excavation damaged zones in the surrounding rock of an underground powerhouse under high in situ stress using an acoustic velocity detecting method |
| url | http://dx.doi.org/10.1155/2020/7297260 |
| work_keys_str_mv | AT liguozhang assessmentoftheexcavationdamagedzonesinthesurroundingrockofanundergroundpowerhouseunderhighinsitustressusinganacousticvelocitydetectingmethod AT dongwang assessmentoftheexcavationdamagedzonesinthesurroundingrockofanundergroundpowerhouseunderhighinsitustressusinganacousticvelocitydetectingmethod AT jiaxingdong assessmentoftheexcavationdamagedzonesinthesurroundingrockofanundergroundpowerhouseunderhighinsitustressusinganacousticvelocitydetectingmethod |