THE DISPLACEMENT AND STRESS FIELD GENERATED BY THE COLLAPSE IN PINGYI COUNTY,SHANGDONG PROVINCE,ON DECEMBER 25, 2015 |
| |
Authors: | WAN Yong-ge JIN Zhi-tong CUI Hua-wei HUANG Ji-chao SHENG Shu-zhong ZHANG Shan-shan LI Cui-qin |
| |
Institution: | 1. Institute of Disaster Prevention, Hebei Sanhe 065201, China;2. Earthquake Administration of Shandong Province, Jinan 250014, China |
| |
Abstract: | A collapse happened in Pingyi County, Shandong Province, on December 25, 2015. The displacement field, stress field and Coulomb failure stress change on the Mengshan frontal fault generated by the collapse are calculated by using point collapse model in isotropic medium. The result shows that: (1) The maximum horizontal displacement is located at the center of the collapse with value of~18mm. The horizontal displacements are greater than 1mm within~5km of the collapse with its direction pointing to the collapse center. The maximum subsidence is located at the center of the collapse with the value of 4mm. The subsidence is greater than 1mm within ~3km of the collapse. The displacement field decays so rapidly that can be ignored at far away from the collapse for the shallow source, which caused local displacement field. (2) Influenced by the free surface, the contraction area stress within ~5km of the collapse with the order of 1000Pa and expansion area stress in farther away areas at depth of 2km are estimated. the expansion area stress of 1000Pa is estimated at the~5km from the collapse center. Then the expansion area stress decays to 100Pa at the distance of ~10km from the collapse. The maximum compressive and extensional principal stresses are estimated as 10000Pa at the depth of 2km. The compressive stress axes present radical direction pointing to the collapse within ~5km of the center. In farther away from the collapse, The extensional principal stress axes present radical direction pointing to the center of the collapse. With farther distance to the collapse, the compressive and extensional stress decay rapidly to the order of 100Pa. (3) The Coulomb failure stress on the northwestern part of the Mengshan frontal fault, which is known as active segment of the Mengshan frontal fault, is decreased by the collapse with maximum value of 2500Pa. Whereas, the Coulomb failure stress on the southeastern part of the Mengshan frontal fault, which is known as left-lateral normal slip fault segment in Quaternary period, is increased by the collapse with maximum of 2400Pa, to which attention would be paid in seismic hazard analysis. |
| |
Keywords: | the 2015 Pingyi collapse in Shandong Province displacement field principal stress Coulomb failure stress change the Mengshan frontal fault |
|
| 点击此处可从《地震地质》浏览原始摘要信息 |
| 点击此处可从《地震地质》下载免费的PDF全文 |
|