| 摘要: |
| 【目的】应用随机介质理论分析黄土暗穴扩展诱发地面沉降的科学规律，为黄土地区公路工程地基设计、施工以及灾害防治提供科学依据。【方法】针对黄土暗穴扩展趋势，借助数值分析软件MATLAB，从暗穴的扩展机理出发研究其扩展形态及过程，并对暗穴扩展诱因进行量化，结合暗穴的临界厚度来判断暗穴的稳定性态，最后利用随机介质理论计算暗穴扩展对地面沉陷的影响。【结果】暗穴抬升、扩容及黄土湿陷诱发地面沉降的分析表明，暗穴抬升过程中，当上覆土体厚度小于临界高度时暗穴会发生坍塌，地面发生约0.25 m的最大沉陷，影响范围约为方圆8.0 m左右；暗穴扩容比暗穴抬升引起的地面沉降量及影响范围更大；随着黄土自重湿陷系数的增大，暗穴引起的地面沉陷量也呈线性增大。【结论】基于随机介质理论的黄土暗穴扩展诱发的地面沉降分析，能够初步预测暗穴塌陷过程对地面的影响；不同深度处黄土的湿陷性差异是黄土暗穴形成的重要原因，黄土的崩解性是诱发地面塌陷的关键因素。 |
| 关键词: 黄土暗穴 地面沉降 随机介质理论 暗穴抬升 暗穴扩容 |
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| 基金项目:国家自然科学基金项目（51179153）；国家自然科学基金创新群体项目（40821001） |
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| Analysis of subgrade settlement induced by expansion of loess hidden holes |
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SU Li-hai,LI Ning,DONG Peng,et al
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| Abstract: |
| 【Objective】This study analyzed the scientific laws of ground subsidence induced by extension of hiding holes with the random medium theory to provide scientific basis in design,construction,disaster prevention and control of loess foundation.【Method】Expansion trend of loess hiding holes was understood with the aid of numerical analysis software MATLAB.Then the expanding pattern and process of hidden holes were proposed and quantified based on the expanding mechanism to determine the stabilization of the hidden holes and analyze the settlement of ground using random medium theory.【Result】During the uplifting process,the hiding holes collapsed when the thickness of the overlying soil was less than the critical height with maximum subsidence of 0.25 m and influencing radius of 8.0 m.The ground subsidence and influence range caused by expansion of hiding holes were larger than by uplifting.With the increase of loess collapsibility coefficient,ground subsidence quantity caused by the hiding holes increased linearly.【Conclusion】Analysis of subgrade settlement induced by expansion of loess hidden holes could predict the influencing of collapse on ground.This method showed that differences in collapsibility of loess at different depths were the main reason of holes formation and the disintegration of loess was the key factor to expansion of hidden holes. |
| Key words: loess hiding hole subgrade settlement random medium theory hiding hole uplift hidden holes expansion |
