降雨入渗对土钉支护稳定性影响研究

发布时间：2018-02-12 12:16

  本文关键词： 地基基础工程 土钉支护 降雨入渗 土钉轴力 稳定性 数值模拟　出处：《郑州大学》2013年硕士论文　论文类型：学位论文

【摘要】：自上世纪90年代以来,随着城市建设的不断发展,建筑趋向高层化,地下空间开发利用的需求量越来越大,相应地基坑工程数量增多。对于工程地质条件相对复杂的地方,基坑开挖施工过程中安全性问题越来越多,特别是降雨、震动等诱发因素对基坑的稳定性有很大不利影响。 土钉支护体系以其构造简单、施工快捷可靠且工期较短、经济性好等优点,在我国基坑围护、边坡支护、隧道围岩支护方面得到了快速推广和应用。但工程实践中,土钉支护体系的失稳破坏事故时常发生,特别是雨季施工过程中,降雨入渗导致的失稳破坏成为土钉支护体系失效的主要原因之一。本文在总结前人相关研究基础上,采用理论分析和数值模拟方法,对不同降雨入渗条件下土钉支护基坑工程的稳定性进行了研究,得到了一些研究成果： (1)在入渗深度和宽度一定的情况下,随着入渗位置从开挖面向远离开挖面方向移动,基坑水平位移和沉降先逐渐增大,随后逐渐减小,在入渗范围内基坑沉降有突增,基坑稳定安全系数随着入渗位置移动,先逐渐减小,然后逐渐增大,在土钉长度末端入渗时,达到峰值,土钉支护稳定性最低。 (2)在入渗深度和位置一定的情况下,随着降雨入渗宽度的增加,基坑水平位移和沉降逐渐增大,入渗范围之外土钉轴力相应逐渐增大,基坑稳定安全系数逐渐减小。 (3)在入渗宽度和位置一定的情况下,随着降雨入渗深度的增大,基坑水平位移和沉降也逐渐增大,入渗范围外土钉轴力也逐渐增大,但当入渗达到一定深度时,基坑水平位移和沉降基本保持稳定,随着入渗深度的继续增加,基本保持不变,基坑稳定安全系数随着入渗深度的增大而减小。 (4)在入渗宽度、深度和位置一定的情况下,随着降雨导致的土体强度衰减程度的增大,基坑水平位移和沉降逐渐增大,入渗范围外的土钉轴力也相应增大,基坑稳定安全系数逐渐减小。
[Abstract]:Since the last century since 90s, with the continuous development of city construction, the construction tends to be high, the development and utilization of underground space demand is growing, the number of the corresponding foundation pit increased. For relatively complicated engineering geological conditions, more and more security problems in the construction process of foundation pit excavation, especially rainfall, have great adverse effects the stability of vibration induced factors of foundation pit.
Soil nailing system with simple structure, convenient construction and reliable short duration, economical and good in our country, bracing of foundation pit, slope support, tunnel has been rapid promotion and application. But in engineering practice, soil nailing system failure accidents often occur, especially the rainy season in the construction process, rainfall infiltration failure becomes one of the main causes of soil nailing failure caused loss. Based on the summary of previous research on the basis of the theoretical analysis and numerical simulation of different rainfall infiltration in soil nailing bracing of foundation pit stability were studied, and obtained some research results:
(1) the infiltration depth and width is certain, with the infiltration from the excavation location oriented away from the excavation surface direction, and the settlement of foundation pit horizontal displacement increases first, then decreases gradually, the infiltration within the scope of foundation settlement has suddenly increased, the stability of foundation pit safety coefficient with infiltration move gradually decreases, then increases gradually, reached a peak at the end of the infiltration length of soil nailing, and the stability of soil nailing is lowest.
(2)鍦ㄥ叆娓楁繁搴﹀拰浣嶇疆涓，

本文编号：1505611