极端降雨作用下红壤土坡响应试验与灾变机理研究

The natural and secondary disasters triggered under extreme weather top various types of ones. And it is one of important scientific problems to be solved in the face of increasingly serious disasters that the effective coping mechanism behind these disasters could be analyzed and established.The methods containing data statistical analysis, outdoor observation, indoor unsaturated soil mechanics test, model test and numerical analysis, are planned to be used conjunctively to investigate systematically both dynamic behavior characteristic and catastrophe mechanism of the red soil slope in various extreme precipitation events.The following three innovative achievements are hope to be obtained. (1) the correlation between extreme rainfall events and landslide disaster will be probed, and the quantitative evaluation of the extreme rainfall events resulting easily in disasters will be built based on the principle of dynamic robust parameter design(2) on the microscopic level, both water-holding and intensity attenuation characteristics of the unsaturated red soil under extreme rainfall conditions will be studied, and the constitutive relation of quantitative indices between shear strength and extreme precipitation events will be clear.3) on the macroscopic level, the dynamic response rules of the red soil slope under the action of extreme precipitation will be clarified, also will be the difficulty in threshold determination of landslide disaster, and following is the clear failure mode and the catastrophe mechanism.Results of the objective are believed to of important academic significance and application value for promoting the progress of science and technology of disaster prevention and reduction, the optimization of slope design, and so.

极端天气引发的自然灾害与次生灾害居各类灾害之首，面对日益严重的灾害事件，剖析其成因并建立有效的应对机制是亟待解决的重大科学问题。本项目拟通过数据资料统计分析、室外监测、室内非饱和土力学试验、模型试验与数值分析相结合的方法，系统研究各类极端降雨事件发展演化过程中红壤土坡动态行为特征与灾变机理。可能获取的创新性成果包括：探明极端降雨事件与滑坡灾害的相关性，并基于动态稳健参数设计原理构建致灾性极端降雨事件的定量化评述模型；从微观角度研究非饱和红壤土在极端降雨工况下的持水特性和强度衰减特征，明确红壤土抗剪强度与极端降雨事件量化指标的本构关系；从宏观角度探明红壤土坡在极端降雨作用下的动态响应规律，解决滑坡灾变的阈值判定难题，明晰破坏模式与灾变机制。本项目的研究对促进防灾减灾科技进步、优化边坡设计理论等领域具有重要的学术意义和应用价值。

极端天气引发的自然灾害与次生灾害居各类灾害之首，面对日益严重的灾害事件，剖析其成因并建立有效的应对机制是亟待解决的重大科学问题。本项目以江西省域范围内典型红黏土边坡为研究对象，依托“萍洪高速公路复建项目”相关路基路堑边坡防护工程，通过数据资料统计分析、室外监测、室内非饱和土力学试验、模型试验与数值分析相结合的方法，系统研究了“短期强降雨”、“持续强降雨”、“持续干旱后强降雨”和“持续阴雨”等各类极端降雨事件发展演化过程中红壤土坡动态行为特征与灾变机理。主要从如下几个方面开展了创新性研究工作：.（1）致灾性极端降雨事件的定义与定量化表达问题：通过对历史滑坡灾害和相关极端降雨事件多源气象指标分析，探索性研究了二者之间的表观统计特征，最终构建了致灾性极端降雨事件的定量化评述模型。.（2）极端降雨作用下非饱和红壤土中细观层面的强度损伤问题：通过对室内外监测数据分析和实施室内非饱和土力学试验，研究了非饱和红壤土的持水特性与强度损伤规律，并最终确定非饱和红壤土抗剪强度与极端降雨事件量化指标的本构关系。.（3）极端降雨作用下红壤土坡的动态行为特征与灾变演化机理问题： 在室内非饱和红壤土力学试验的基础上，通过实施室内模型试验，并对比分析数值试验结果，获取极端降雨作用下红壤土坡动态行为特征，从宏观角度剖析灾变发展演化机理问题。.本项目的研究深入剖析了红黏土边坡灾变的动态演化机理，对于“浙闽赣丘陵山地群发性滑坡”的防治，相关边坡工程的防护，岩土工程的优化设计等具有重要理论价值和工程实践指导作用。