城市地铁浅埋隧道爆破振动及空气冲击波传播规律探索
发布时间：2018-09-01 16:30
【摘要】：浅埋隧道爆破对周边建筑物及施工人员造成的影响是修建城市地铁时无法回避的问题。由于复杂地质条件会导致不同的爆破施工方案,就要对不同地质情况下的浅埋隧道爆破振动及井下空气冲击波传播规律进行研究。本文基于大连地铁浅埋隧道爆破施工实践,用不同的方法对不同地质下的爆破振动进行研究。在参考大量国内外学者研究成果的基础上,根据实际情况,给出了适用于大连地铁隧道爆破的振动速度安全允许标准,并于中风化泥灰岩、中风化石灰岩及中风化白云质灰岩等地质条件下进行爆破振动测试。实验结果表明,在爆破近区,爆破振动合速度(Vmax)与三向最大速度的合值(VHmax)相差为15%左右,因此采用爆破振动合速度来作为测试参考值是可行的；通过分析大量测试结果表明,浅埋隧道爆破的水平方向的振动主频通常要比垂直方向的低,而建筑物对低频有选择放大的效应,测试时也应注意水平方向的振动,而不是一味的关注垂直方向的振动；通过对爆破振动测试结果进行振动功率谱密度分析可以得出,振动功率谱密度图谱可以清晰的看出爆破在低频下的能量,适用于敏感建筑的爆破设计及测试；并通过实验验证了浅埋隧道存在“空洞效应”；给出了上述三种城市典型地质条件下的萨道夫斯基衰减曲线,可供未来类似工程借鉴。通过在隧道内进行爆破空气冲击波超压测试,对井下空气冲击波传播规律进行探索,结果表明：相比于地面爆破振动速度,隧道爆破冲击波超压在雷管小段别下峰值明显,可以用来检验掏槽区域的爆破设计质量；通过对冲击波超压进行噪声分析,结果表明井下爆破空气冲击波超压衰减速度慢并伴随着高分贝的噪声,不同的掏槽方式对冲击波超压值有明显影响；对测试结果进行冲量分析,结果表明冲击波负压绝对值虽然没有超压大,但是由于其作用时间长,导致冲击波负压冲量值与超压冲量值相差不大甚至超过超压冲量,应予以重视；根据测试结果对冲击波衰减曲线进行拟合,给出了不同工况下空气冲击波超压的能量逸出系数并进一步得出不同工况下的冲击波安全允许距离。
[Abstract]:The influence of shallow tunnel blasting on surrounding buildings and construction personnel is an unavoidable problem in the construction of urban subway. Because the complicated geological conditions will lead to different blasting construction schemes, it is necessary to study the blasting vibration of shallow buried tunnel and the propagation law of underground air shock wave under different geological conditions. Based on the blasting construction practice of shallow buried tunnel in Dalian Metro, the blasting vibration under different geological conditions is studied by different methods in this paper. Based on the research results of a large number of scholars at home and abroad, and according to the actual situation, the allowable standard of vibration velocity safety for blasting in Dalian subway tunnel is given, and the standard for the safety of vibration velocity is given in the middle weathering mudstone. Blasting vibration test was carried out under geological conditions such as medium weathered limestone and medium weathered dolomite. The experimental results show that the difference between the combined velocity of blasting vibration (Vmax) and the maximum velocity of three directions (VHmax) is about 15%, so it is feasible to use the combined velocity of blasting vibration as the reference value. The main frequency of horizontal direction vibration of shallow buried tunnel blasting is usually lower than that of vertical direction, and the building has selective amplification effect on low frequency, so we should pay attention to horizontal direction vibration when testing, rather than pay attention to vertical direction vibration. By analyzing the vibration power spectrum density of blasting vibration test results, it can be concluded that the vibration power spectrum density spectrum can clearly see the energy of blasting at low frequency, which is suitable for the blasting design and test of sensitive buildings. The existence of "cavity effect" in shallow tunnel is verified by experiments, and the Saadolski attenuation curve under the three typical geological conditions mentioned above is given, which can be used for reference by similar projects in the future. By testing the overpressure of blast air shock wave in tunnel, the propagation law of underground air shock wave is explored. The results show that compared with the vibration velocity of ground blasting, the peak value of blasting shock wave overpressure in tunnel is obvious under the detonator segment. It can be used to test the blasting design quality in the cut area, and by noise analysis of shock wave overpressure, the results show that the attenuation speed of blast wave overpressure in underground blasting is slow and accompanied by high decibels noise. The results of impulse analysis show that the absolute value of shock wave negative pressure is not as large as that of shock wave, but because of its long acting time, different cutting methods have obvious influence on shock wave overpressure, and the test results show that the absolute value of shock wave negative pressure is not as large as that of shock wave overpressure. It is necessary to pay attention to the difference between shock wave negative pressure impulse value and over pressure impulse value, and to fit the shock wave attenuation curve according to the test results. The energy escape coefficient of air shock wave overpressure under different working conditions is given and the safe allowable distance of shock wave under different working conditions is obtained.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U231.3;U455.6
本文编号：2217746
[Abstract]:The influence of shallow tunnel blasting on surrounding buildings and construction personnel is an unavoidable problem in the construction of urban subway. Because the complicated geological conditions will lead to different blasting construction schemes, it is necessary to study the blasting vibration of shallow buried tunnel and the propagation law of underground air shock wave under different geological conditions. Based on the blasting construction practice of shallow buried tunnel in Dalian Metro, the blasting vibration under different geological conditions is studied by different methods in this paper. Based on the research results of a large number of scholars at home and abroad, and according to the actual situation, the allowable standard of vibration velocity safety for blasting in Dalian subway tunnel is given, and the standard for the safety of vibration velocity is given in the middle weathering mudstone. Blasting vibration test was carried out under geological conditions such as medium weathered limestone and medium weathered dolomite. The experimental results show that the difference between the combined velocity of blasting vibration (Vmax) and the maximum velocity of three directions (VHmax) is about 15%, so it is feasible to use the combined velocity of blasting vibration as the reference value. The main frequency of horizontal direction vibration of shallow buried tunnel blasting is usually lower than that of vertical direction, and the building has selective amplification effect on low frequency, so we should pay attention to horizontal direction vibration when testing, rather than pay attention to vertical direction vibration. By analyzing the vibration power spectrum density of blasting vibration test results, it can be concluded that the vibration power spectrum density spectrum can clearly see the energy of blasting at low frequency, which is suitable for the blasting design and test of sensitive buildings. The existence of "cavity effect" in shallow tunnel is verified by experiments, and the Saadolski attenuation curve under the three typical geological conditions mentioned above is given, which can be used for reference by similar projects in the future. By testing the overpressure of blast air shock wave in tunnel, the propagation law of underground air shock wave is explored. The results show that compared with the vibration velocity of ground blasting, the peak value of blasting shock wave overpressure in tunnel is obvious under the detonator segment. It can be used to test the blasting design quality in the cut area, and by noise analysis of shock wave overpressure, the results show that the attenuation speed of blast wave overpressure in underground blasting is slow and accompanied by high decibels noise. The results of impulse analysis show that the absolute value of shock wave negative pressure is not as large as that of shock wave, but because of its long acting time, different cutting methods have obvious influence on shock wave overpressure, and the test results show that the absolute value of shock wave negative pressure is not as large as that of shock wave overpressure. It is necessary to pay attention to the difference between shock wave negative pressure impulse value and over pressure impulse value, and to fit the shock wave attenuation curve according to the test results. The energy escape coefficient of air shock wave overpressure under different working conditions is given and the safe allowable distance of shock wave under different working conditions is obtained.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U231.3;U455.6
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