【作者】 尹泉；

【导师】 彭振斌； 彭文祥；

【作者基本信息】 中南大学 ， 地质工程， 2011， 硕士

【摘要】 充气锚杆是一种全新结构的锚杆,它是针对软土地区岩土工程支护难题而提出一种新型锚杆。充气锚杆就是在钢管端部外套一段外表粗糙的橡胶膜,上下两端用钢环将橡胶膜紧固在钢管上,在包裹橡胶膜段的钢管部分钻适量充气小孔,利用钢管对橡胶膜充气,使锚杆端部橡胶膜膨胀,挤压周围土体形成一个扩大头,利用橡胶膜与土体之间摩擦力和扩大头端头阻力提供锚杆的抗拔力。充气锚杆具有施工简便,快捷,易操作；用材简单,并可回收利用；锚杆施工完毕可立即提供全部锚固,大大节约了施工工期；无废液、废气、无噪音、施工环保；可在水下施工,为海洋、港口水下作业机器提供抗浮锚固力等一般注浆锚杆没有的优点。目前充气锚杆的研究在国外还处于起步阶段,而在国内还没有相关研究报道,因此本文主要从充气锚杆的各类基本实验出发,对充气锚杆的极限抗拔力及变形进行了详细的分析,并对充气锚杆的锚固机理及承载力公式进行了一些探索性的分析,主要研究工作及结论如下：(1)分析充气锚杆的结构,对充气锚杆的材料选材进行了深入的研究,得到了制作充气锚杆的最佳材料。并根据充气锚杆抗拔试验对充气锚杆的性能要求,制作了用于室内及现场抗拔实验用的充气锚杆。(2)设计制作了整套充气锚杆室内及现场抗拔试验装置,对充气锚杆进行了大量的抗拉试验,得到了许多宝贵的实验数据,并分析了影响充气锚杆极限抗拔力的影响因素。(3)设计了一套可以控制充气锚杆膨胀体积的试验装置,分别对充气锚杆膨胀体在砂土及软土中的变形进行了反复的测定,得到了充气锚杆充气压力与膨胀体体积的关系数据。(4)把充气锚杆的膨胀体近似的看成是圆柱体,运用圆孔扩张理论分析膨胀体在土体中变形情况,分析了充气锚杆的锚固机理,并给出了充气锚杆抗拔力的经验公式。更多还原

【Abstract】 Inflatable anchor is one which was applied in the latest. It was aimed to solve the retaining project of civil engineering in soft soil area. Inflatable anchor is that steel pipe was setted by rough rubber mold with steel rings fixed. The segment of steel pipe with rubber mold was drilled proper small holes with it inflate gas. By the way of inflating air with the steel pipe, rubber film in the end of the steel pipe expanded to squeeze the surrounding soil. Anti-pull force was provided by friction between rubber film and soil and the resistance of enlarge head. Inflatable anchor was constructed simple, quick and easy to operate; Timber is simple and can be recycled; Once the anchor was constructed, it can provide the all anchor force which saved the construction period; The anchor was constructed with no waste liquid and gas、no noise which could protect environment; Inflatable anchor could be constructed under the water to provide the anchor resistance for ocean and port engineering which the grouting anchor could not complete.At present the studies about inflatable anchor is still in the initial stage abroad and there is a little report about the field in domestic. This article mainly analyzes ultimate pullout force and deformation of the inflatable anchor in detail based on all kinds of basic experimental, it also gives an exploratory analysis of the anchoring mechanism and bearing capacity formula.The main research works and conclusions are as follows:(1) The structure of inflatable anchor was analyzed and thorough research was carried out on choice of materials which obtained the best material. According to the performance requirements based on the uplift test, the inflatable anchor was designed for laboratory test and field experiment.(2) The device for laboratory test and field experiment was designed. The influence factors of anchor limit resistance was analyzed based on the lots of valuable test data which was concluded by a lot of tensile test.(3) A set of device was designed which was used to control the swelling volume of inflatable anchor. Mass data about the relation between the inflation pressure and the swelling volume of inflatable anchor was obtained by the test of the deformation of inflatable anchor in sand and soft-soil.(4) The inflation body of inflatable anchor was taken as cylinder, the deformation condition of the soil was analyzed with cavity expansion theory and the anchor mechanism was analyzed, which the empirical formula of anti-pull force of inflatable anchor was concluded.更多还原