【作者】 吴青山；

【导师】 张继春； 赵永明；

【作者基本信息】 西南交通大学 ， 建筑与土木工程， 2004， 硕士

【摘要】 渝怀(重庆至怀化)铁路的修建面临着大量的顺层石质路堑爆破开挖施工。由于爆破地震的作用，很可能造成边坡岩体发生局部或整体层裂，使岩体的自稳能力降低，甚至可能导致已成形的路堑边坡滑坡或坍塌。这不仅影响施工的顺利进行，而且使支挡防护施工难度增大，工程费用增加，甚至造成安全事故。 为了能够很好地解决这个问题，本文通过在渝怀铁路DK375～DK377区段内的顺层边坡岩体进行的爆破地震效应和爆破层裂效应试验，获得了采用不同爆破方法时岩体的地震波衰减规律和爆破引起的边坡岩体层裂范围以及相应的岩体质点振动速度分布规律，确定出了顺层边坡岩体的爆破振动速度控制标准，并提出了切实可行的减震爆破技术措施。 深孔爆破时路堑横向的地震波衰减参数为K=240.40、α=1.54，路堑纵向为K=298.48、α=1.63；小台阶爆破的相应值为K=42.96、α=1.58，路堑纵向为K=58.92、α=1.52；小台阶光面爆破路堑横向为K=35.03、α=1.21，路堑纵向为K=72.24、α=1.67。 通过质点振速和岩体层裂范围的耦合分析，确定出该试验区段边坡岩体爆破开挖发生层裂时的临界质点振速为25.3cm／s。深孔爆破引起的岩体层裂范围最大，当单孔装药量5～40kg时，其值可达7.36～14.73m。小台阶爆破产生的岩体层裂范围一般都在2.5m以内，比深孔台阶爆破小得多。 本文研究提出了深孔爆破与缓冲爆破相结合的预留保护层分部开挖方案。深孔爆破与缓冲爆破的单孔(或单段)装药量分别控制在15kg、5kg以内、孔内采用间隔装药结构以及孔内与孔间顺序微差起爆这一系列降震技术措施，可有效控制顺层边坡岩体质点振速和层裂范围，降低以至消除顺层边坡岩体的爆破层裂效应。 在运用此项研究成果的渝怀铁路工点中，根据其工点的现场实际情况，采取相应的降低爆破地震效应的具体技术措施，因而没有发生因开挖爆破不当而引起的任何质量和安全事故，边坡稳定、坡面平整，完全符合设计要求和验交规范，施工进展顺利，取得了良好的经济效益和社会效益。更多还原

【Abstract】 The construction of Yuhuai railway from Chongqing to Huaihua is faced with a great lot of cutting blasting engineering in layered rock masses. The seismic action in blasting results in the part or whole lamination breakage of slop rock mass in all probability, which will reduce the slope stability, even induce the cutting sliding or collapsing by any possibility. These not only affect the construct, but also add to the difficulties of protection construction. Thus, the engineering cost increases, even the safety accidents easily occur.In order to solve this problem, the field experiments for seismic effect and lamination effect of layered slope rock mass at Yuhuai railway DK375-DK377 were carried out. The attenuation laws of seismic waves for different blasting methods were obtained. The lamination ranges of rock masses caused by deep-hole and short-hole blasts were measured and the corresponding distribution laws of particle vibration velocities were also gotten. The control standard of vibration in the layered rock slope blasting was determined and moreover, the technical measures of blasting for reducing vibration were put forward.For a deep-hole blasting, the attenuation parameters of seismic waves along the cutting cross-sectional direction are K= 240.40, 1.54 and along the longitudinal direction K= 298.48 1.63. For a short-hole bench blasting, the corresponding attenuation parameters are K=42.96, a= 1.58 and K=58.92 1.52, respectively. For a short-hole smooth blasting, the attenuation parameters are K=35.03 1.21 and K= 72.24 1.67,respectively.Through the comparing analyses between the particle vibration velocity and the lamination range of rock mass, the critical vibration velocity of rock particles while rock masses occur lamination cracks in the region have been determined, which is 25.3 cm/s. The lamination range resulting from a deep-hole blasting is greatest. When the charge of a blast hole is 5 ~ 40 kg, the lamination range reaches 7.36-14.73 m.The lamination range induced by a short-hole bench blasting is much smaller than that of a deep-hole blasting, which does not exceed 2.5 m.The subsection construction scheme of which remains a protected layer and combines the deep-hole blasting with the cushion blasting is presented in this thesis. Some technical measures of reducing vibration, such that the single-hole charges of the deep-hole blasting and cushion blasting are controlled within 15kg and 5kg respectively and that the interval charging construction in a blast hole and the sequence micro-second ignition technique between blast holes as well as their internals are applied, can effectively control the particle vibration velocity of layered slope rock mass and the lamination range of rock mass. These can also reduce even avoid the lamination effect of rock blasting.The research results mentioned above were used in a few of some projects in Yuhuai railway construction. According to the concrete conditions of these construction sites, the corresponding technical measures for reducing seismic effect of blasting were taken and therefore, no quality safety accident resulting from excavating blasting occurred. The slope surface formed by blasting is stable and smooth, which accords with the demands of design and the acceptance criterion. The construction achieved better economic and social benefits.更多还原