【作者】 张忠伟；

【导师】 朱传云；

【作者基本信息】 武汉大学 ， 水工结构工程， 2004， 硕士

【摘要】 在许多水利水电工程中，爆破施工在隧洞的开挖工程中经常用到，不可避免的会出现爆破振动对开挖洞自身及邻近的建筑物的影响问题。尤其是在有多条引水发电隧洞同时施工或是前后施工的时候，会遇到发电引水隧洞的爆破开挖造成对邻近的既有引水隧洞的爆破振动问题。当爆破振动超过一定强度时，会对混凝土结构以及围岩造成损伤甚至破坏。因此十分有必要了解爆震动力荷载作用对隧洞衬砌和围岩稳定的影响及特点，并对爆破振动安全控制标准提出合理建议，为爆破设计与施工提供科学依据。 在实际的工程中，通常以实测质点振速作为安全控制标准并且根据监测数据回归出爆破振速的衰减规律，以便对可能产生的振动强度进行预测。本文利用大型通用有限元分析软件ANSYS-LS／DYNA，分析了在爆破振动荷载下，圆环形隧洞衬砌结构的动态响应和隧洞爆破振动沿不同方向衰减的规律。 本文总结了应力波的理论和爆破地震波的传播和衰减规律；归纳了振动方程的推导过程及解法；计算了爆破荷载作用下衬砌及围岩的振速；用应力波的反射理论解释了混凝土衬砌不同部位的振速的分布和变化；着重分析了隧洞轴向沿洞顶的径向振动速度的衰减规律；并且分析了爆破振动频率的影响。 通过计算和比较，有以下几点认识： 1．既有隧洞中静水压力对爆破荷载造成混凝土内外壁振动的影响较小。 2．低频波比高频波的危害更大。 3．爆破振动荷载作用时间越长，对围岩和混凝土衬砌的危害越大。 4．爆破振动速度在竖直向有放大效应，对于距爆源等距离的竖直向的爆破振速大于水平向。 5．隧洞开挖的轴向洞顶距离掌子面3倍洞径处会出现一个爆破振速增大的区域。 6．既有隧洞的迎爆侧振速要大于背爆一侧，衬砌内壁因为临空面的存在武次犬.学硬了.学应老戈撇萝 造成振速放大。7.在实际工程中爆破振动速度的衰减主要是介质的阻尼所决定，但同时 受到临空面、转角等的影响会出现衰减过程中局部振速放大。更多还原

【Abstract】 Blast construction is always used in the excavation of tunnel in many hydroelectric engineerings.It is unavoidable to appear the questions that the effects on the tunnel itself and neighboring constructions by blast vibration. Especially we will meet the question of blast vibration on the existent tunnel by blast excavation of hydroelectric diversion tunnel under construction of many tunnels or two following tunnels. When the intensity of blast vibration exceed the criterion value,it will damage even destroy the concrete construction and rocks.So it is very essential to understand the effect and characteristic of blast vibration dynamic load on concrete lining and rock. The suggestions for safety criterion of blasting vibration should be proposed ,and the regulation can be offered for practical design of blasting construction.In the factual engineering, safe control criterion is often in virtue of measure the spot’s blast vibration velocity and regression analyze attenuation equation of blast vibration so that forecast possible coming into being vibration intensity.In this article, author has done some research on dynamic response on cirque tunnel concrete and different direction attenuation equation under blast vibration dynamic load by making use of general FEM analysis software-ANSYS-LS/DYNA.This thesis, author has summarized the theory of passes and attenuation equation of stress wave;deduced process and solution of vibration equation; calculated the velocity of concrete lining and rock under blast vibration dynamic load; explained concrete different part’s blast vibration velocity and distributing changes by theory of Stress reflecting; emphasized attenuation equation of radial velocity on axis top of tunnel; at last analyzed the effect by the blast vibration frequency.By means of calculation and anslysis ,some conclusions are reached as follows:(1) Ihe effect is smaller that is made by water pressure on vibration caused by blast dynamic load inside and outside of existent tunnel.(2) Low frequency stress wave does more damage.(3) As far as blast vibration dynamic load is concerned,the time is longer and the damage on concrete and rock is bigger.(4) Blast vibration velocity has magnify effect in the vertical direction,the vibration value of vertical direction is bigger than horizontal direction at the same distance to blast place.(5) Radial velocity is bigger on axis top of tunnel at the distance of 3 times of radius to free face.(6) As blast vibration velocity of existent tunnel, it is bigger that is closer to blast spot, it is bigger in Interior side of concrete lining because of free face.(7) In the factual engineering blast vibration velocity’s attenuation is decided by medium damp,but it has magnify effect in some area because of free face and corner.更多还原