Shallow Layer Tomography Study on Tongmai⁃Lulang Section of Sichuan⁃Tibet Railway 川藏铁路通麦‒鲁朗段浅层结构背景噪声成像

Hua，Qian1,3,4; Pei，Shunping1,2,3; Guo，Zhen5; Cai，Fulong1,2,3; Ding，Lin1,2,3; Xue，Xiaotian1,3; Li，Lei1,3; Li，Jiawei1,3; Liu，Hanlin1,3; Liu，Wei1,3

2022-09-01

10.3799/dqkx.2022.111

地球科学   Impact Factor & Quartile

1000-2383

In order to explore the characteristics of shallow geological structure of Tongmai-Lulang section of Sichuan-Tibet railway, effectively assess the risk of geological disasters along the railway and ensure the safety operation of railway facilities, high resolution S-wave velocity structure of shallow crust is obtained by ambient noise tomography based on waveform data of short-period seismic dense array in this paper, combined with geological survey results, the geometric morphology and activity characteristics of faults along the section are accurately determined. S-wave velocity structure and geological survey results show that there are good correspondences between low-velocity zones and faults distributed along the section, and F1-F6 control the geometry of the low-velocity zones below. Combining with geological analysis and seismology data, we can infer that: (1) The seismogenic structure of Milin Ms6.9 earthquake may belong to a fault system composed of a series of imbricated and back-thrust faults. The seismic activities of the fault system tend to the northwest end, where the seismic risk is higher. La Yue tunnel is located in the northwest of the fault system, which may have strong seismic activity in the future. (2) Xixingla fault, the southern branch of Jiali fault, is active as a concealed fault in the section. F5 and F6 may both belong to the Gongriga-Buqu branch with high-angle W-dip and strong fracture zone characteristics which may be related to the continuous high-angle right-handed thrust shear movement of Jiali fault. (3) The dense faults in the study area control the circulation of underground heat flow. The dissolution of high-temperature fluid intensifies the fragmentation degree of rock mass in the tectonic process, reduces the stability of rock mass, and easily leads to various types of geological disasters. Therefore, the Tongmai-Lulang section of Sichuan-Tibet railway should be equipped with effective monitoring and early warning system and emergency mechanism to deal with geological disasters and ensure the normal operation of tunnels and railway facilities.

ambient noise tomography S ‐ wave velocity structure seismology short ‐ period seismic dense array Sichuan ‐ Tibet railway

Chinese

Others

2-s2.0-85139871932

Scopus

1.Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing,100101,China
2.State Key Laboratory of Tibetan Plateau Earth System，Resources and Environment（TPESRE）,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing,100101,China
3.University of Chinese Academy of Sciences,Beijing,100049,China
4.Shaanxi Earthquake Agency,Xi’an,710068,China
5.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Hua，Qian,Pei，Shunping,Guo，Zhen,等. Shallow Layer Tomography Study on Tongmai⁃Lulang Section of Sichuan⁃Tibet Railway 川藏铁路通麦‒鲁朗段浅层结构背景噪声成像[J]. 地球科学,2022,47(9):3447-3462.

Hua，Qian.,Pei，Shunping.,Guo，Zhen.,Cai，Fulong.,Ding，Lin.,...&Liu，Wei.(2022).Shallow Layer Tomography Study on Tongmai⁃Lulang Section of Sichuan⁃Tibet Railway 川藏铁路通麦‒鲁朗段浅层结构背景噪声成像.地球科学,47(9),3447-3462.

Hua，Qian,et al."Shallow Layer Tomography Study on Tongmai⁃Lulang Section of Sichuan⁃Tibet Railway 川藏铁路通麦‒鲁朗段浅层结构背景噪声成像".地球科学 47.9(2022):3447-3462.