基坑工程变形及支护结构与土相互作用研究

【作者】 周波；

【导师】 彭社琴；

【作者基本信息】 成都理工大学 ， 岩土工程， 2006， 硕士

【摘要】 基坑变形包括支护结构的水平位移、基坑外围土体沉降、基坑底部隆起等，是控制支护结构安全稳定、基坑周边环境安全及基坑工程顺利施工的关键，同时是研究支护结构与土相互作用的基础。基坑变形形式、计算方法、变形限值等方面的深入研究成为基坑工程支护结构设计的重点和难点。本论文结合润扬大桥北锚锭基坑工程的实测资料，对基坑工程中的变形进行了分析，并结合数值模拟研究了墙体刚度、支撑间距、支撑截面尺寸、土体刚度等因素对变形的影响。研究结果初步表明：①支护结构最大水平位移出现的位置一般在0.58倍墙体深度附近；②若不考虑降水引起的坑外土体固结沉降，地表最大沉降量和墙体水平位移最大值基本呈线性关系：d_vmax=0.65×d_hmax；③该深基坑地表沉降曲线呈槽形，降水引起的地表沉降值较明显，大于墙体位移引起的地表沉降。④该深基坑地下连续墙的水平位移与土压力类型有较好的对应关系，工况6以前，土压力主要表现为静止土压力，工况6开始明显转为主动土压力；⑤影响基坑变形的因素主要有墙体刚度（墙体的厚度）、支撑间距、支撑截面尺寸等，数值分析结果表明，对墙体水平位移影响最大的是支撑间距，当支撑间距增加或者减少1m时，最大墙体水平位移可增减25％～30％，而墙体厚度、支撑截面尺寸影响则相对较小。更多还原

【Abstract】 The deformation of deep foundation engineering includes deflection of retaining wall, the surface settlement behind the wall and the basal heave. It is the most important factor to ensure the pit’s stability, the environmental safety around the pit, successfully constructing. It is base element for research of interaction between soil and support structure. Study on deformation mode, calculation method and limit value are the most importance and difficulty for deep pit engineering. This paper study upon monitoring information of anchor deep foundation engineering of Runyang Changjiang River Highway Bridge. Analysis its deformation. Numeric simulation method is also involved in to study upon the impact factor of deformation, such as: rigidity of retaining wall, space between bracing, cross section size of the Bracing and rigidity of soil, the study come to the conclusion as below:① The maximal horizontal displacement usually occur at 0.58 depth of the wall.② If don’t take precipitation into account, then, the maximum settlement and maximum horizontal displacement can be express as d_vmax=0.65 ×d_hmax.③The settlement curve of this pit is groove like. Settlement caused by precipitation is greater than that cause by displacement of wall.④ Horizontal displacement of the wall and Earth pressure mode have better consistency. Earth pressure is at rest before condition 6, and it turn into active pressure under condition 6.⑤ Factors affecting pit deformation include rigidity of wall, space between Bracing and cross section size of the Bracing, among these factors space between Bracing is most effective. If 1m was added to original space, the maximum horizontal displacement of wall can be reduced to 70%-75%. The two other factor have smaller affect on the deformation of wall.更多还原