具有蠕变特点滑坡的加速度变化特征及临滑预警指标研究

RESEARCH ON ACCELERATION VARIATION CHARACTERISTICS OF CREEP LANDSLIDE AND EARLY-WARNING PREDICTION INDICATOR OF CRITICAL SLIDING

具有蠕变特点的滑坡从变形启动到整体滑动破坏这一过程一般要经历初始变形、等速变形和加速变形3个阶段,且不同阶段有其不同的变形特点。依托于大量滑坡变形监测数据,对滑坡从开始变形到失稳破坏全过程中的累积位移、变形速率和加速度等的变化规律进行系统地分析和研究,发现加速度的变化表现出与累积位移和变形速率完全不同的特点。在斜坡变形进入临滑阶段之前的所有时间段内,加速度值基本在0附近作上下振荡,而一旦进入临滑阶段,加速度则骤然剧增,呈现出明显的突变特征。也就是说,加速度在斜坡进入临滑阶段前后呈现出迥然不同的特点。针对此特点,提出基于加速度的滑坡临滑预警方法和临滑预警指标δ。根据该指标,可望实现滑坡的自动临滑预警。

The process of the landslide from beginning deformation to global sliding failure generally includes the initial deformation, constant speed deformation and accelerated deformation. Different deformation stages have their own different characteristics. The understanding of inherent characteristics of various stages to provide the basis for landslide warning and forecasting is the hot issue for scholars. Based on a large number of landslide deformation monitoring data, the change laws of accumulative displacement, deformation rate, acceleration, etc. are researched： and it is found that the changes of acceleration performance have different characteristics with accumulative displacement and deformation rate. Over the period before the landslide reaches critical sliding stage, the acceleration value is basically around O. While landslide is under critical sliding stage, the acceleration is suddenly increased and shows significantly catastrophic characteristics. In other words, the acceleration before and after the landslide is under critical sliding stage shows completely different characteristics. Aiming at the above characteristics, the early-warning prediction indicator 8 for critical landslide sliding is proposed based on the acceleration. According to the indicator, automatic early-warning predication of critical landslide sliding is expected to achieve.