【作者】 许海亮；

【导师】 张继春；

【作者基本信息】 西南交通大学 ， 岩土工程， 2003， 硕士

【摘要】 掘进爆破技术作为岩质地区浅埋隧道工程的一种主要施工方法，在施工中不可避免地要产生爆破地震效应。对爆破地震效应的控制不仅直接影响到爆破质量、隧道施工效率和工程经济效益，而且还影响到隧道围岩的稳定、隧道支护的效果以及周围建筑物或构筑物的安全。而要达到有效地控制爆破地震效应就必须对爆破地震波传播中的相关特性进行研究。 本文以穿越地表高层的渝怀铁路人和场浅埋隧道工程为背景，进行掘进爆破地震效应的现场试验，通过测量爆破引起的地表和隧道围岩的质点振动速度，研究地表与隧道内的爆破地震波传播特征。对比分析掌子面前后地表振动速度的变化特征发现，隧道成洞区的地表振动速度大于未成洞区的地表振动速度，即：在成形隧道区存在爆破震动的放大效应，其放大系数达1.3倍以上。同时对比分析隧道内开挖断面变大区域的质点振动速度数据发现，该区域同样存在爆破震动的放大效应。 通过地表楼房地震效应的现场试验，研究掘进爆破地震波沿楼房高度的变化特征发现，同一楼层的质点垂直振动速度一般大于相应的水平振动速度，前者为后者的1.2～4倍，而质点垂直振动频率更接近于楼房的自振频率。同时发现地表高层存在“滤波作用”，即爆破地震波频率随楼房高度的增加而趋近于楼房的自振频率。随着振动频率趋近于楼房的自振频率，质点振动速度也出现了增大趋势。 为了较准确的计算钻孔爆破引起的质点振动速度，本文在萨道夫斯基公式的基础上考虑了钻孔爆破自由面面积的影响，提出了钻孔爆破振动速度计算公式。通过实测振动速度数据的验证，由该式计算出的质点振动速度比萨道夫斯基公式的计算值更接近于实测值，其比例达80％以上。更多还原

【Abstract】 The technique of driving blasting is used as a main constructive way in shallow tunnels in rocky zone. By this way, blasting seismic effect is inevitable. The control of blasting seismic effect is concerned with not only the blasting quality, the tunnel constructive efficiency and the benefit of the tunnel construction, but also the stability of the surrounding rock, the effect of tunnel timbering and the safety of buildings around the tunnel. In order to control the blasting seismic effect effectively, the blasting seismic waves’ characters should be studied.In view of the Ren Hechang shallow tunnel in Yuhuai railway, which will dig under two high buildings, the field experiments on seismic effect have been done. By measuring vibration velocities of particles in the ground and the surrounding rock of the tunnel, the blasting seismic waves’ characters have been studied. By analysing the change character of the vibration velocities of the front and the back per face, it is found that the vibration velocities at the ground of the back pre face are larger than those of the front. That is, at the ground of the back pre face, there is the magnification effect of the vibration velocities, the magnification coefficient is no less than 1.3. Analysing and comparing the vibration velocities at the different regions of the digging surface changed, there is also the magnification effect of the vibration velocities in these regions.The field experiments have been done on seismic effect of the building. By studying the change character of the blasting seismic waves’ along the vertical direction of the building, it is found that the vertical vibration velocities are larger 1.2-4 times than the horizontal vibration velocities at the same floor. The vertical vibration frequency is much closer to the self-frequency of the building than the horizontal vibration frequency at the same floor. Along the vertical direction of the building, the blasting seismic waves’ frequency becomes closer to the self-frequency. As a result,the vibration velocities have the trend to increase.In order to calculate the particle vibration velocity in drilling blasting accurately, the corresponding formula has been brought forward. Compared with the results of the Sodev’s empirical formula, the results of the formula are much closer to the values of the actual vibration velocities. 80% of the results of the formula are better than those of the Sodev’s empirical formula.更多还原