| 地震作用下康定市郭达山危岩带运动特征 |
| |
| 作者姓名： | 徐伟 朱志明 铁永波 袁传保 |
| |
| 作者单位： | 1.中国地质调查局成都地质调查中心,四川 成都 610081;2.成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川 成都 610059;3.武汉地质工程勘察院有限公司,湖北 武汉 430050;4.中铁二院工程集团有限责任公司,四川 成都 610031 |
| |
| 基金项目： | 中国地质调查局“川西地区特大地质灾害链调查评价(编号: DD20221746)”项目资助 |
| |
| 摘 要： | 康定地区多为深切河谷地貌,山坡陡峻,基岩裸露,崩塌落石多发,地震频发。为开展地震作用下崩塌运动特征和规律研究,以康定市郭达山危岩带为研究对象,采用颗粒流离散元软件(particle flow code in 2 dimension,PFC2D)模拟危岩带不同部位崩塌源(坡顶孤石、坡体上部碎裂岩体、坡体中部老崩塌堆积体、坡体下部块状危岩)在面波震级(surface ware magnitude,Ms) 8.0地震作用下的运动特征和破坏过程。研究结果表明: ①坡顶孤石质量越小越易启动,孤石越接近球形越易发生倾覆和滚动,沿临空面飞出后运动类型以坠落、碰撞、滚动为主,坡顶孤石的运动速率最大时达11.8 m/s; ②坡体上部碎裂岩体破坏过程可分为裂隙延伸贯通—启动坠落—碰撞解体—滚动堆积4个阶段,位于碎裂岩体上部的块石运动距离最远,达269 m; ③老崩塌堆积体块石自前向后形成碎屑流,沿坡面运动类型以滚动、碰撞为主; ④下部块状危岩运动特征为启动—滑动—挤压—解体—再滑动—再挤压—堆积; ⑤不同部位的崩塌在运动过程中块石会发生碰撞、摩擦、挤压、解体,快速消耗自身动能,导致运动距离和速率骤降。采用离散元模拟能够更全面更精细化的认识深切河谷区的崩塌,可为崩塌灾害的工程治理和山区城镇的防灾减灾提供科学依据。
|
| 关 键 词： | 康定市 郭达山危岩带 运动特征 |
| 收稿时间： | 2022-03-03 |
Movement characteristics of rockfall under earthquake in Guoda Mountain of Kangding City |
| |
| Authors: | XU Wei ZHU Zhiming TIE Yongbo YUAN Chuanbao |
| |
| Institution: | 1. China Geological Survey of Chengdu Center, Sichuan Chengdu 610081, China;2. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Sichuan Chengdu 610059, China;3. Wuhan Institute of Geological Engineering Exploration Co., Ltd, Hubei Wuhan 430050, China;4. China Railway Eryuan Engineering Group Co., Ltd, Sichuan Chengdu 610031, China |
| |
| Abstract: | The landforms in Kangding City are deep-cutting valley, with steep slopes and exposed bedrocks, and the falling rocks and earthquakes occurred frequently in this area. In order to carry out the study on the characte-ristics and laws of the collapse movement under the earthquake action, the researchers in this paper take rockfalls in Guoda Mountain of Kanding City as a case study and adopt the Particle Flow Code software PFC2D to simulate the movement characteristics and failure process rockfall at different locations (boulder stone on the top of slope, catallactic rock mass on the slope, collapse accumulation in the middle of slope, block rockfall under the slope) under Ms 8.0 earthquake. The results are as following: ① The boulder stones on the top of slope with small mass are easy to be started, and the boulder stones with nearly spherical shape are easy to be capsized and rolled. The movement types after departing along the free face are falling, colliding and rolling, with the highest rate of 11.8 m/s. ② The failure process of catallactic rock mass on the slope can be divided into four stages, including extending - penetrating of fracture, starting - falling, crashing - disintegrating, and rolling - stacking. The block rock mass above the catallactic rock mass moves furthest, up to 269 m. ③ The collapse accumulation forms a debris flow from front to back, and its movement types along the slope are rolling and colliding. ④ The movement characteristics of fallrocks in the lower part of the mountain are starting, sliding, squeezing, disintegrating, re-sliding, re-squeezing and accumulating. ⑤ The collision, friction, extrusion and disintegration occurred in the collapses in different locations during movement, which quickly consumed their own kinetic energy and caused sharply dropping in distance and speed. The discrete element simulations could help refined understanding of collapse in deep-cutting valleys, which provides some scientific basis for the project management of collapse and disaster prevention in mountainous regions and cities. |
| |
| Keywords: | Kangding City rockfall belt of Guoda Mountain movement characteristics |
|
| 点击此处可从《》浏览原始摘要信息 |
| 点击此处可从《》下载免费的PDF全文 |
|
