湿陷性黄土地区深基坑及边坡锚杆支护受力性能应用研究

【作者】 陈广峰；

【导师】 米海珍； 朱彦鹏；

【作者基本信息】 甘肃工业大学 ， 结构工程， 2001， 硕士

【摘要】 目前，锚杆已成为土木工程中作为支护结构的常选构件，锚杆的使用越来越广泛，但锚杆的受力规律随土质和安装角不同而异。本文试图探讨锚杆应用于黄土地区时其受力的规律及最佳安装角，鉴于此，笔者在室内以黄土作为支护介质进行了锚杆受力分析的试验，试验锚杆的类型为拉力型和压力型两种，安装角（埋入土中的角度）为30°、45°、60°三种。由试验结果分析得知：其受力规律与其它支护介质中的规律相近，按理论推导得到了最佳安装角α_opt的计算公式，通过数值计算给出了其简化公式：α_opt≈60°-φ（其中φ为土的内摩擦角）；由剪力沿锚杆长度的分布情况，提出了剪力沿杆长分布的“黄金分割”原则及锚固体有效锚固长度的建议值。 本文还对兰州地区黄土的湿陷性进行了探讨工作，利用实际工程工作采样研究，发现在兰州黄河Ⅲ级阶地上的黄土湿陷性有悖于随深度增大而逐渐减小的规律。为究其原因，做了土样的化学成分及结构分析，得知其中的Na₂CO₃。含量较全国黄土的该含量高出4.3倍，这是一个新测设的数据，由于测试较少，还难以对其给出定论，希望能引起同行及黄土工程界的重视和探讨。更多还原

【Abstract】 Nowadays, anchor is one of the most chosen as a member of supporting structure in Civil Engineering. The stress law of anchor various with different soil and different embedding angle. The author tries to discuss the stress law and best embedding angle of anchor when it is used in Loess. In order to get specific data, series of tests for stress law on anchor are performed within the lab, with Loess as the supporting media. Included are tensile and pressure anchors in different embedding angles: 300 45 0 600 . The findings indicate: the stress law of anchor is similar to some other supporting media. And theoretically, a calculating formula for best embedding angle a is deduced, which is simplified as a ~60O ?is the internal friction angle). Meanwhile, the golden mean principle for variation of shearing force along the anchor is brought forward, according to the experimental data. The Loess collapsibility in Lanzhou is also discussed exploratively in this paper. Testing to the samples form some projects shows the collapsible coefficient of high-grade Loess in Lanzhou doesn抰 agree with the law that collapsible coefficient should decrease with the depth downward. In order to find out the reasons, the soil sample are analyzed in chemical component and structure, which demonstrates the Na2CO~ content is 4. 3 times more than that of ordinary soil in China. The new datum can not be verified definitely for lack of sufficient tests. However, it is deserved to be taken seriously by relevant researchers.更多还原