预应力锚杆格构梁模型试验及计算方法研究

【作者】 王娟娟；

【导师】 门玉明；

【作者基本信息】 长安大学 ， 地质工程， 2006， 硕士

【摘要】 近年来，预应力锚杆格构梁越来越多地应用于边坡加固工程，其原理是通过钢筋混凝土格构梁将锚杆巨大的锚固力传递给坡体，以此改善坡体应力状态，调用坡体自稳能力。与挡土墙及悬臂式抗滑桩等加固方法比较，预应力锚杆格构梁属于一种主动加固方法。目前，对锚杆格构梁的设计计算方法研究较少。因此，本文通过对预应力锚杆格构梁模型试验数据的分析对其内力计算方法作了进一步的研究，并探讨了预应力锚杆格构梁的受力特点及规律。 文中首先介绍了在滑坡治理工程中常用的治理方法，指出了现有预应力锚杆格构梁内力计算方法的优缺点，得出了采用预应力锚杆格构梁治理土质或岩质边坡时，应用倒梁法以及Winkler模型都不能很好地解决锚杆格构梁内力计算的认识。 通过模型试验分析，认为对于锚杆格构梁(纵、横梁)，当纵梁和横梁截面尺寸一致时，其地基反力的分布规律基本相同。即在悬臂端及梁跨中处地基反力较小，在纵、横梁交叉处由于受到锚杆锚固力的作用使格构梁所受地基反力增大。文中还对锚杆格构梁的计算方法进行了探讨，将格构梁拆分成横梁与纵梁进行单独分析，将其分别视为弹性地基梁。在半无限弹性介质模型的基础上利用级数法的原理计算了格构梁(纵、横梁)的弯矩。 根据理论计算弯矩图得出：土体不同方向的弹性模量会影响格构梁的受力，弹性模量较小时格构梁柔度系数小而弯矩较大，弹性模量较大时格构梁柔度系数大而弯矩较小；模型试验数据得出的弯矩值与计算弯矩值较为接近，说明在锚杆格构梁的内力及变形分析中，采用半无限弹性介质理论是可行的，能够满足工程实际的需要；通过将试验结果与理论计算结果的对比认为，由于在格构梁节点处作用锚杆锚固力，格构梁的受力变得不均匀，总体说来在靠近梁中部的节点处受力最大，悬臂端受力最小；在梁中部锚杆作用点处出现弯矩极大值，在锚杆之间受力较小。这一方面要求格构梁设计时应充分重视梁中部的配筋，钢筋接头宜设于梁端部；另一方面说明在布置格构梁钢筋时不宜按最大弯矩设通长筋，以免造成较大的浪费。更多还原

【Abstract】 In recent years, the prestressed anchor lattice beams are applied in the slope reinforcement engineering more and more. It is an active reinforcement method, which can improve slope stress state and initiate it’s body’s self-stability by passing the anchor’s huge anchoring force to the slope body through the reinforced concrete lattice beam. Currently, the study on the anchor lattice beam’s design and calculating method is very scarce. Therefore, on the basis of analyzing the prestressed anchor lattice beam model test’s data, further studies on the calculating method of the internal force is made in this paper, and the force characters and regulation are also discussed.Firstly, common methods in the controlling engineering of landslide are introduced, the merits and demerits of the existing prestressed anchor lattice beam internal force calculating method are also pointed out. While using the prestressed anchor lattice beam to control the close-grained soil slope and rock slope, the reverse beam method or the Winkler model can’t treat the calculating method or the anchor lattice beam internal force rationally.Through the model test analysis, as to the anchor lattice beam, when the size of the carling matches with that of crossbeam, the foundation’s counterforce condition can be considered to be the same basically. The counterforce in the cantilever at the end and the middle of the beam is small, while in the crossing position of the carling and crossbeam the lattice beam’s counterforce is augment as the effect of the anchoring force. This paper also discusses the anchor lattice beam’s calculating method, during the course of study the lattice beam is divided into two parts: carling and crossbeam, and these two parts are regarded separately as elastic foundation. Based on the semi-infinite elastic media model, this paper calculated the lattice beam’s moment by using series method principle.Through the moment graph of theory calculating, the results are as follows: the elastic modulus of different directions in soil can affect the lattice beam’s更多还原