【作者】 徐亮；

【导师】 孟益平；

【作者基本信息】 合肥工业大学 ， 桥梁与隧道， 2018， 硕士

【摘要】 随着我国经济的不断发展,城市人口密度持续的增大,缓解城市交通压力已经成为大城市在经济发展过程中需要着重解决的问题,迫使政府在城市轨道交通建设事业方面投入大量的资金,来满足城市交通需求;地铁是轨道交通建设中重要的一项交通建设方式,目前,国内许多大城市都在建设、或即将建设地铁隧道;在地铁隧道开挖方式中,钻爆法是常用的施工方式,这是因为在经济和工艺等技术方面考虑,钻爆法是硬岩区域最适合的施工方案;但是钻爆法施工难免伴随着强烈的地震效应,对地面既有建筑物结构和稳定性产生不利的影响,甚至可能会产生破坏的损伤,尤其是紧贴既有建筑物情况下在硬岩区域开挖中等断面隧道,对爆破振动效应的控制要求会更高,这就让传统的乳化炸药爆破开挖方式不能够满足爆破振动效应控制要求,必须寻求其它能满足要求的地铁隧道开挖方式进行隧道施工;从韩国引进的SWELLNEX金属膨胀剂能够很好的控制爆破振动效应。满足紧贴既有建筑物施工环境下地铁隧道开挖要求。本文依托青岛地铁一期工程3号线青岛火车站西端暗挖区段地铁工程为背景;该区段下穿既有地铁2号线车站及益群地下商场,为站前区间及换乘通道,既有建筑物底板距离隧道临空面较近,在下穿地铁2号线车站主体区段部分隧道顶板甚至紧贴2号线底板,且前期地铁2号线隧道开挖过程中对围岩有扰动,围岩的完整性有所降低,需要对爆破振动效应进行严格的控制。采用钻爆法进行隧道爆破开挖的方式有多种,本文主要对乳化炸药爆破方式、金属膨胀剂爆破方式以及静态破碎法爆破方式进行研究比较。通过将理论分析与现场试验情况相结合的方法,总结分析金属膨胀剂爆破开挖方式和静态破碎法爆破开挖方式各自的优越性以及在使用时需要注意的施工细节;运用数值模拟方法研究乳化炸药爆破开挖方式和金属膨胀剂爆破开挖方式在爆破减振效应方面各自的优越性,并结合现场实际监测结果对比验证。具体研究内容可概括为以下几个方面:⑴、对紧贴既有建筑物以及围岩作安全性评估,根据国内外爆破振动效应控制的安全标准,结合青岛地铁3号线施工环境,制定本文研究的隧道工程施工环境下相对应的爆破振动速度安全标准。⑵、在施工现场进行金属膨胀剂和静态破碎剂爆破开挖试验,并实时监控爆破振动速度,观察围岩破碎效果,对两种爆破方式进行总结,分析两种爆破开挖方式各自的优缺点以及在施工时需要注意的施工细节,归纳总结出哪种爆破方式更适合本文研究的施工环境下进行隧道爆破开挖施工。⑶、为确保能满足拟定的爆破安全振速,并且能达到理想的隧道爆破开挖效果,在现场进行多次金属膨胀剂爆破试验,并对每一次试验结果进行总结、改进,确定炮孔布置间距、深度以及起爆开挖顺序。⑷、运用显示动力分析软件ANSYS/LS-DYNA3D,对乳化炸药爆破开挖方式和金属膨胀剂爆破开挖方式进行数模拟分析,计算出哪种施工方式满足爆破振动速度要求,并将满足要求的施工方式模拟结果与现场监测结果进行对比验证,评价两种爆破方式各自的优缺点。⑸、综合三种爆破方式的特点,总结归纳出最适合在紧贴既有建筑物施工环境下进行隧道爆破开挖的施工方式。更多还原

【Abstract】 With the continuous development of China’s economy,the urban population density continues to increase,and alleviating urban traffic pressure has become a problem that large cities need to focus on in the process of economic development,forcing the government to invest a lot of money in the construction of urban rail transit.Meet the needs of urban transportation;the metro is an important transportation construction method in the construction of rail transit.At present,many large cities in China are building or are about to build subway tunnels;in tunnel excavation methods,drilling and blasting method is a common construction method.This is because the drilling and blasting method is considered to be the most suitable construction method for hard rock areas in terms of economy,technology,and other technical aspects;however,the drilling and blasting method is inevitably accompanied by strong earthquake effects.It has an adverse effect on the existing building structure and stability on the ground and may even result in damage.In particular,in the case of existing buildings,excavation of medium-section tunnels in hard rock areas will have higher requirements for the control of blasting vibrations.This will allow conventional emulsification.Explosive blasting excavation method can not meet blasting vibration effect control requirements,must seek other excavation tunnel construction that meet the requirements of the subway tunnel;imported from South Korea SWELLNEX metal expanders can be well controlled blasting vibration effect.Meet the requirements of excavating subway tunnels in the construction environment of existing buildings.This article relies on the underground construction of the underground excavation section of the Qingdao Railway Station on the third line of the first phase of the Qingdao Metro Line 3.This section passes through the existing Metro Line 2 station and the Yiqun underground shopping mall,which is the front station interval and transfer path.The floor of the existing building is close to the adjoining surface of the tunnel,and the tunnel roof below the main section of the Metro Line 2 station is even close to the floor of the 2nd line,and the surrounding rock is disturbed during the excavation of the subway line 2 in the early stage.The integrity of the surrounding rock has been reduced,and the blasting vibration effect needs to be strictly controlled.There are many methods of tunnel blasting excavation using the drill-and-blast method.This paper mainly studies the explosive blasting method,metal expansive blasting method and static crushing method.By combining the theoretical analysis with the field test,the advantages of metal expansive blasting excavation method and static crushing method in blasting excavation method are summed up,and the construction details that need attention during use are summed up;The explosive blasting excavation method and metal expansive blasting excavation method have their own advantages in the aspects of blasting vibration damping effect,and are compared and verified with actual monitoring results on the spot.The specific research content can be summarized as the following aspects:(1)For the safety assessment of existing buildings and surrounding rocks,according to the safety standards for the control of blasting vibration effects at home and abroad,in conjunction with the construction environment of Qingdao Metro Line 3,the corresponding blasting under the construction environment of the tunnel project studied in this paper is formulated,vibration speed safety standards.(2)Explosion excavation tests of metal expansive agent and static crusher are conducted at the construction site,and the blasting vibration velocity is monitored in real time to observe the crushing effect of the surrounding rock.Two types of blasting modes are summarized and the advantages and disadvantages of the two types of blasting excavation are analyzed.As well as construction details that need attention during construction,it is concluded which blasting method is more suitable for tunnel blasting excavation construction in the construction environment studied here.(3)In order to ensure that the proposed blasting safety vibration rate can be met and the desired tunnel blasting excavation effect can be achieved,a number of metal expansive agent blasting tests are performed at the site,and the results of each test are summarized and improved to determine the blast hole layout,spacing,depth,and blasting excavation sequence.(4)Using the display dynamic analysis software ANSYS/LS-DYNA3 D,simulate and analyze the explosive blasting excavation method and the metal expansive blasting excavation method,and calculate which construction method meets the blasting vibration speed requirement.The coincident simulation results of the construction method are compared with the on-site monitoring results to verify the respective advantages and disadvantages of the two blasting methods.(5)To synthesize the features of the three blasting methods and sum up the construction methods that are most suitable for tunnel blasting excavation in close proximity to the existing building construction environment.更多还原