嵌入扩体式锚杆及其在基坑工程中的应用

发布时间：2018-08-21 20:26

【摘要】：在建筑工程、水利水电工程、交通工程、矿业工程等与国防民生息息相关的工程中,岩土锚固技术是一种解决岩土加固问题较有效的方法。对于一些较为陡峭的高边坡工程,需抗浮设计的地下工程,深、大基坑工程,城市市政的高压输水管工程等技术难度较高、风险系数较大的工程,特别是当此类工程位于软土较厚或土层较差的沿海地区时,普通锚杆所能提供的承载力和实际施工效果已经很难满足实际工程建设和正常使用的需求。在海南土质基坑支护的大量工程实际的调查研究的基础上,结合岩石锚杆的研究与应用现状,本文研发出了一种可在一定程度上通过增加锚杆锚固力的办法来增加锚杆抗拔力的嵌入扩体式锚杆,并在海口市某一基坑支护工程中进行了应用,对边坡土体中分别加入普通锚杆和嵌入扩体式锚杆,通过三维有限元软件模拟和对比计算,得出了嵌入扩体式锚杆在增加基坑的安全系数和控制基坑变形等方面较优越于普通锚杆的结论,降低了支护成本,保证了基坑安全,取得了良好的效果。本文主要成果如下： (1)通过对国内外锚杆种类和各种锚杆在不同类型工程中的应用的特点及典型案例的总结,并就目前锚杆因施工工艺和土层问题所造成的承载力不理想的问题进行了分析,指出了目前钢筋锚杆在基坑支护工程中存在许多隐患和弊端。在此基础上,研发出了嵌入扩体式锚杆,通过增加扩锚板来增大锚固力,从而增大锚杆抗拔力的一种新型的土体锚杆。获得了国家实用新型发明专利(专利证号ZL201420731101.1；发明人：卫宏、韩宏超；授权时间：2015年4月1日)。 (2)以海口市某一较为典型的基坑边坡工程实例为依托,结合该工程的工程地质条件、水文地质条件,利用ABAQUS三维有限元软件分别对普通钢筋锚杆和嵌入扩体式锚杆锚固两种情况下的同一工程进行模拟,分别得到两种情况下的锚杆应力应变云图和边坡位移云图等,从边坡位移、锚杆杆体的应力应变、经济成本和施工效果等方面对两种锚杆进行对比分析,均得出了嵌入扩体式锚杆相比普通锚杆在解决边坡安全稳定和控制变形上有一定的优势的结论,优势主要表现为嵌入扩体式锚杆抗拔力较大,采用嵌入扩体式锚杆的基坑安全稳定系数较高；经济投入成本较低；施工效果较好,减少水泥砂浆等材料的浪费等。
[Abstract]:In construction engineering, water conservancy and hydropower engineering, traffic engineering, mining engineering and so on, geotechnical anchoring technology is an effective method to solve the problem of geotechnical reinforcement. For some steep high slope projects, underground projects requiring anti-floating design, deep and large foundation pit projects, high pressure water transmission pipes in urban municipalities, etc., have higher technical difficulties and higher risk factors. Especially when this kind of project is located in the coastal area where the soft soil is thicker or the soil layer is poor the bearing capacity and actual construction effect provided by ordinary anchor can hardly meet the demand of practical engineering construction and normal use. On the basis of the investigation and research on a large number of projects of soil foundation pit support in Hainan, combined with the research and application status of rock bolt, In this paper, a kind of embedded and expanded anchor rod which can increase the anti-pulling capacity of anchor rod by increasing the anchoring force to some extent is developed and applied in a foundation pit support project in Haikou City. Common anchor rod and embedded expanded anchor rod are added to the soil mass of slope, and the simulation and comparison are carried out by means of 3D finite element software. It is concluded that the embedded expanded anchor is superior to the common anchor in increasing the safety factor of the foundation pit and controlling the deformation of the foundation pit, which reduces the supporting cost, ensures the safety of the foundation pit and achieves good results. The main achievements of this paper are as follows: (1) by summarizing the characteristics and typical cases of various kinds of anchors and their application in different types of engineering, The paper also analyzes the problem that the bearing capacity of anchor rod caused by construction technology and soil layer is not ideal, and points out that there are many hidden dangers and disadvantages in foundation pit supporting engineering. On this basis, a new type of soil anchor is developed, in which the anchor force is increased by increasing the anchor expansion plate and the pull-out strength of the anchor rod is increased. The national utility model invention patent (patent certificate number ZL201420731101.1; inventor: Wei Hong, Han Hongchao; authorization time: April 1, 2015,). (2) is based on a typical excavation slope engineering example in Haikou City. Combined with the engineering geological conditions and hydrogeological conditions of the project, the same project under the two conditions of common reinforcement anchor and embedded expanded anchor is simulated by using ABAQUS three-dimensional finite element software. The stress-strain cloud diagram and slope displacement cloud diagram of the two kinds of anchors are obtained, respectively. The two kinds of anchors are compared and analyzed from the aspects of slope displacement, stress and strain of bolt body, economic cost and construction effect, etc. It is concluded that the embedded expanded anchor has some advantages in solving the slope safety and stability and controlling the deformation compared with the common anchor. The main advantage is that the embedded expanded anchor has greater pull-out resistance. The safety and stability coefficient of foundation pit with embedded expanded anchor rod is higher, the cost of economic input is lower, the construction effect is better and the waste of cement mortar and other materials is reduced, etc.
【学位授予单位】：海南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753

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