人工气候箱环境下膨胀土裂隙演化定量分析与预测模型

项目名称： 人工气候箱环境下膨胀土裂隙演化定量分析与预测模型

项目编号： No.51279200

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 水利工程

项目作者： 刘观仕

作者单位： 中国科学院武汉岩土力学研究所

项目金额： 80万元

中文摘要： 膨胀土的胀缩性与裂隙性所诱发的工程灾害具有反复性和长期性，并因全球气候异常所致极端干旱和雨涝而加剧。课题以膨胀土边坡稳定与防护工程为背景，探索裂隙演化定量评价和深度测试方法，揭示原状膨胀土裂隙平面演化和深度扩展规律，建立相关理论及预测模型。首先通过人工气候箱模拟干湿循环大气环境，促控箱内膨胀土裂隙发育，采用摄影图像形态学方法定量分析裂隙特征，通过裂隙分层图像三维重建手段研究深度测试方法，据此获取多组合试验数据，定量揭示浅层膨胀土裂隙演化规律及与表面温、湿度及持续时间、土体初始含水率等参数的关系，探求裂隙平面与深度特征的关联性，进而基于膨胀土裂隙的平面与深度特征关系建立其开展深度经验预测模型，基于Markov模型建立适用于膨胀土裂隙表面扩展规律的随机过程模型，并实现对气候条件下裂隙演化的数值模拟和预测。成果对丰富膨胀土的非饱和理论研究、推进膨胀土边坡灾害评估及坡面防护理论与设计具有积极意义。

中文关键词： 裂隙；膨胀土；数字图像；人工气候箱；定量化分析

英文摘要： Expansive soils,with remarkable expansion, shrinkage and cracks, result in complicated and long-term damages to projects during engineerring constructions, which are deepened by extreme droughts and floods due to global abnormal climate changes.Under the background of expansive soil slopes and protection projects,this research subject is expected to, explore the quantitative evaluation method for cracks assesment and method for depth measuring,reveal the laws of crack evolution in plane and depth,create related theories and forecasting models.Firstly, cyclic wetting and drying generated by artificial climate box simulating actual atmosphere circumstance, is used to prompt and control the evolution of cracks of expansive soil in the box.Secondly, the information of cracks comprised in images by camera is drawn out to evaluate the features of cracks quantitatively, and the method for crack depth measurement is studied according to three-dimensional reconstruction from layered-images of cracks.Based on the test data with the methods, the relationships between crack evolution of shallow in-situ expansive soil and surface temperature,moisture and initial water content,etc., and the relationships between plane and depth characters of cracks ,are explored.Thirdly,the empirical model of crack depth forecasting and stoch

英文关键词： crack；expansive soil；digital image；artificial climate box；quantitative analysis