富水破碎围岩隧道施工技术研究

发布时间：2018-10-20 07:23

【摘要】：在隧道修建过程中会经常遇到富水破碎带,如何选择正确的施工方法一直以来都是一个重要课题,本文以乐园隧道富水破碎带施工技术为背景,主要研究了富水破碎隧道如何进行合理防排水和如何选择最优开挖工法。本文通过对大量文献资料归纳总结,通过理论分析得出隧道富水破碎区渗流场与应力场相互影响机理,并以此为基础提出合理防排水措施。结果表明：(1)地下水通过对围岩结构面产生物理化学反应影响应力场；(2)地下水通过力学作用改变围岩应力场分布。应力场通过影响岩体体积应变和孔隙率影响岩体渗透性。对于隧道防排水选择以“以堵为主、综合治理”为原则,通过超前地质预报探明掌子面前方富水破碎情况,对富水破碎带实施注浆进行止水,并于破碎带中线布置排水孔进行适当排水。通过非线性有限元软件ADINA分别对富水破碎带未注浆止水进行开挖和注浆止水进行开挖模拟,结果表明：未注浆止水对隧道稳定不利,应在开挖前采取注浆止水。对隧道按全断面法、台阶法和分部开挖法进行开挖模拟,对比分析不同开挖方法下的应力分布、锚杆轴力变化等方面,结果表明：(1)采用分部开挖法开挖,其应力和锚杆轴力均最小,所需支护力最小；(2)采用全断面法开挖,其应力最大,锚杆轴力也最大,所需支护力最大；(3)台阶法介于二者之间,但比采用全断面法对隧道稳定性大得多。结合数值模拟结果,考虑到各种开挖方法施工经济性与对掌子面稳定性影响,乐园隧道围岩破碎带采用台阶法施工实际意义最大。
[Abstract]:In the course of tunnel construction, it is often met with water-rich broken zone. How to choose the correct construction method has always been an important subject. The background of this paper is the construction technology of water-rich broken zone in paradise tunnel. This paper mainly studies how to carry out reasonable waterproofing and drainage and how to select the optimal excavation method for water-rich broken tunnel. In this paper, the mechanism of interaction between seepage field and stress field in water-rich broken area of tunnel is obtained through theoretical analysis through summarizing a large number of literature data, and based on this, reasonable waterproof and drainage measures are put forward. The results show that: (1) the stress field of the surrounding rock is affected by the physical chemical reaction of the groundwater, and (2) the stress field distribution of the surrounding rock is changed by the mechanical action of the groundwater. The stress field affects the permeability of rock mass by influencing the volume strain and porosity of rock mass. For the selection of tunnel waterproofing and drainage, the principle of "plugging is the main, comprehensive treatment" is taken as the principle. Through the advanced geological forecast, the situation of water-rich breakage in front of the face of the tunnel is proved, and grouting is carried out to stop the water in the water-rich fracture zone. Drainage holes are arranged in the middle line of the broken zone for proper drainage. In this paper, the excavation of water-rich broken zone without grouting is simulated by the nonlinear finite element software ADINA. The results show that the non-grouting is unfavorable to the stability of the tunnel, so the grouting should be adopted before excavation. The excavation simulation of the tunnel is carried out according to the full section method, step method and partial excavation method. The stress distribution under different excavation methods and the change of anchor axial force are compared and analyzed. The results show that: (1) excavation method is used to excavate the tunnel. The stress and bolt axial force are the minimum, and the supporting force is the least; (2) the stress is the largest, the anchor axial force is the largest, and the supporting force is the largest; (3) the step method is between the two methods, the stress is the largest, the anchor shaft force is the largest, and the support force is the largest. But the stability of tunnel is much better than that of full section method. Combined with the numerical simulation results, considering the construction economy of various excavation methods and the influence on the stability of the face, it is of great practical significance to use the step method to construct the broken zone of surrounding rock of Paradise tunnel.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.4

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