多级楔形掏槽微振动爆破控制技术

发布时间：2018-10-08 07:01

【摘要】：采用钻爆法施工的隧道,施工过程中不可避免地要产生爆破振动,不仅威胁周围建(构)筑物的安全而且危害居民的身心健康。如何在不影响或少影响施工效率的前提下,尽可能降低爆破振动,已成为隧道爆破施工首要解决的问题。为降低地铁车站爆破施工对周围建筑物的振动扰动、提高爆破施工效率,本文以青岛地铁2号线一期工程土建01标延安路车站近接建筑物爆破施工为背景,在爆破振动控制标准严格要求的条件下,从理论分析和现场试验两个方面,对多级楔形掏槽减振机理、不同掏槽爆破参数对地表建筑物振动影响、掏槽爆破振动影响因素权重及自由面与最小抵抗线对隧道爆破振动影响进行了研究,并将研究成果应用于地铁车站爆破施工中,不仅将爆破振速控制在设计允许的范围内,而且提高了施工效率,保证了工期。本文的主要研究结论有:(1)多级楔形掏槽的减振机理可以从单段最大起爆药量和自由面个数两个方面进行分析。(2)多级楔形掏槽在浅埋暗挖隧道近接建筑物爆破施工中具有较好的减振效果。其比钻孔、爆破振动控制、炮孔利用率、炸药雷管单耗等经济技术指标均优于大直径中空孔直眼掏槽。多级楔形掏槽的第二级、第三级掏槽逐孔起爆,减振效果显著。在炮孔深度1.1m,单孔装药量0.3kg的情况下,较掏槽孔成对起爆,掏槽孔逐孔起爆产生的峰值振速最高可降低67.5%。同时掏槽孔逐孔起爆不会降低掏槽的炮孔利用率。(3)爆破振动控制严格时,宜选用三级以上的多级楔形掏槽,各级掏槽的炮孔倾角从低级向高级逐渐增大,第三级掏槽炮孔深度应大于其他掏槽孔,第一级与第二级掏槽、第二级与第三级掏槽的间距不宜超过0.4m,第二级掏槽孔数布设5对,其他级布设4对,同级掏槽孔宜采用先中间后两边起爆顺序,段最小间隔时间25ms以上,可取得较好的减振效果。(4)采用灰色关联分析法,以现场实测数据为样本,结合MATLAB程序计算,得出多级楔形掏槽爆破振动可控影响因素的重要度排序,从大到小依次为:掏槽区比钻孔、第二级掏槽单段最大起爆药量、第一级掏槽单段最大起爆药量、第二级掏槽孔炮孔深度、第三级掏槽孔炮孔深度、掏槽级数、第三级掏槽单段最大起爆药量、同级掏槽孔起爆顺序、段最小间隔时间。(5)爆破振动受自由面与最小抵抗线共同影响。在爆心距、单段最大起爆药量相同而自由面个数不同时,自由面数量越多,位于隧道斜上方的质点振动强度越小;自由面个数相同而最小抵抗线方向不同时,质点振动强度也不同,其中最小抵抗线方向竖直向上时,质点振动强度最小;质点振动强度还与最小抵抗线大小有关,相同条件下,最小抵抗线大,质点振动强度也大。本文的研究结论可为类似工程建设提供参考。
[Abstract]:Blasting vibration is inevitable in the construction process of tunnels constructed by drilling and blasting method, which not only threatens the safety of the surrounding buildings, but also endangers the physical and mental health of the residents. How to reduce blasting vibration as far as possible without affecting construction efficiency or less has become the most important problem in tunnel blasting construction. In order to reduce the vibration disturbance caused by the blasting construction of subway station and improve the efficiency of blasting construction, this paper takes the blasting construction of the adjacent building of No. 01 Yanan Road Station of Qingdao Metro Line 2 as the background. Under the strict requirements of blasting vibration control standards, the mechanism of multi-stage wedge cutting vibration reduction and the effect of different cutting blasting parameters on the vibration of ground buildings are studied from two aspects: theoretical analysis and field test. The influence factors weight of cutting blasting vibration and the influence of free surface and minimum resistance line on tunnel blasting vibration are studied. The research results are applied to the blasting construction of subway station, and not only the blasting vibration velocity is controlled within the scope of design allowable. Moreover, the construction efficiency is improved and the construction period is guaranteed. The main conclusions of this paper are as follows: (1) the vibration absorption mechanism of multistage wedge cutting can be analyzed from two aspects: the maximum explosive quantity of single stage and the number of free surface. It has better vibration absorption effect. The economic and technical indexes such as specific drilling, blasting vibration control, hole utilization ratio and unit consumption of explosive detonator are better than large diameter hollow hole straight hole cutting. The second stage and the third stage of the multi-stage wedge-shaped cutting are hole-by-hole priming, and the effect of vibration reduction is remarkable. When the depth of the hole is 1.1 m and the charge amount of the single hole is 0.3kg, the peak vibration velocity can be reduced by 67.5% as compared with that of the cut hole in pairs, and the peak vibration velocity produced by the hole-by-hole initiation can be reduced up to 67.5%. At the same time, the hole-by-hole blasting will not reduce the hole-to-hole utilization ratio. (3) when the blasting vibration is strictly controlled, the multi-stage wedge-shaped cutting should be selected, and the hole inclination of each level gradually increases from the lower level to the higher level. The depth of the gunhole at the third level shall be greater than that of the other cutting, the first and the second shall be cut, the spacing between the second and the third shall not exceed 0.4 m, the number of the second and the second shall be arranged in 5 pairs, and the other level shall be arranged in 4 pairs. It is advisable to adopt the initiation sequence between the middle and the two sides of the same cutting hole, and the minimum interval time of the section is above 25ms. (4) the method of grey relational analysis is used to calculate the vibration of the same cutting hole, and the field measured data is taken as the sample, and the calculation is combined with the MATLAB program. The order of importance of controllable factors for vibration control of multi-stage wedge cut blasting is obtained. The order from large to small is as follows: cut area ratio drilling hole, maximum initial explosive quantity of second cut single section, maximum initiation charge of the first cut single section. The second cutting hole depth, the third cutting hole depth, the cutting series, the third cutting single section maximum initiating charge, the same level cutting hole initiation sequence, (5) blasting vibration is affected by free surface and minimum resistance line. The larger the number of free surfaces, the smaller the vibration intensity of particles located above the tunnel, and the same number of free surfaces and different directions of minimum resistance lines. The particle vibration intensity is also different when the minimum resistance line direction is vertical upward and the particle vibration intensity is related to the minimum resistance line size. Under the same conditions the minimum resistance line is large and the particle vibration intensity is large. The conclusion of this paper can provide reference for similar engineering construction.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.41

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