MHB碎石化施工对临近构筑物振动影响试验与数值模拟研究

发布时间：2018-02-17 05:12

本文关键词： 水泥混凝土路面碎石化振动监测安全距离　出处：《兰州理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：碎石化技术因能有效防止反射裂缝,节约资源,降低路面修复成本等优点,近年来被广泛应用于旧水泥混凝土路面改建工程中。但由于碎石化破碎机械冲击能量大,施工过程中巨大的冲击波会对沿线建筑物产生振动影响甚至破坏作用,如何判定碎石化施工的影响范围和程度,避免对周边环境的不利影响,是安全顺利使用这项技术的难点。本文首先基于波动理论研究冲击引起的振动波在土体中的传播特性和衰减规律,通过对埋地管涵承受振动荷载能力的计算,确定冲击荷载作用下管涵的安全埋深;然后以山东省S245改建工程为依托进行现场振动监测,分析碎石化施工对邻近建筑物、埋地管涵、边坡的振动影响,提出邻近构筑物碎石化施工振动的控制标准和保护措施;最后采用ANSYS/LS-DYNA有限元程序开展冲击振源位置、冲击能量变化对旧路面板破碎程度影响的研究,分别从振源位置、冲击能量、与振源水平间距、埋置深度的变化四个方面分析埋地管道在冲击荷载作用下的动力响应,为MHB碎石化施工提供参考。主要结论如下:(1)碎石化施工冲击和响应具有瞬态振动的特点,是一种低频高幅振动,与地震作用下持续强迫振动有本质区别。不同冲程下的振动响应衰减规律相同,在振源附近以竖向振动为主。(2)碎石化施工振动会影响邻近建筑物的安全和居民的舒适度,当冲程分别为0.8m、1.0m、1.2m时,临近建筑物水平安全距离分别为14m、18m、20m,居民可以接受的振动距离为24m、29m、31m;冲程1.0m时道路下埋混凝土管涵安全埋深为2.4m,路堤边坡上的建筑物水平安全距离为12m。(3)锤击位置对路面结构振动影响较大,当作用于板角时对路面结构的冲击效果最明显,路面板最容易破碎,所以在施工过程中通常先从板角进行破碎,逐步向板中推进。在影响管涵振动速度的四个因素中,参数敏感性由大到小依次为:管道与振源水平距离、管涵埋深、荷载作用位置和冲程。实际施工过程中采取避让、减小锤击频率、降低冲程等方法来降低对邻近结构的振动影响。
[Abstract]:Gravel technology has been widely used in the reconstruction of old cement concrete pavement in recent years because it can effectively prevent reflection cracks, save resources and reduce the cost of pavement repair. The huge shock wave in the construction process will have vibration effect or even damage effect on the buildings along the line. How to determine the scope and extent of the impact of the gravel construction to avoid the adverse impact on the surrounding environment, It is difficult to use this technique safely and smoothly. Firstly, based on wave theory, the propagation characteristics and attenuation law of vibration wave caused by shock in soil are studied, and the bearing capacity of buried pipe culvert under vibration load is calculated. The safe buried depth of pipe culvert under impact load is determined, and the vibration effect of gravel construction on adjacent buildings, buried culvert and slope is analyzed based on the S245 reconstruction project in Shandong Province. The paper puts forward the control standard and protection measures of the vibration in the gravel construction of adjacent structures. Finally, the ANSYS/LS-DYNA finite element program is used to carry out the research on the impact vibration source location, and the influence of the impact energy change on the broken degree of the old road slab is studied, respectively from the vibration source location. The dynamic response of buried pipeline under impact load is analyzed from four aspects: impact energy, horizontal distance between vibration source and buried depth. The main conclusions are as follows: the impact and response of crushed stone construction have the characteristics of transient vibration, which is a kind of low frequency and high amplitude vibration. Under different stroke, the vibration response attenuation law is the same. The vertical vibration is the main vibration near the vibration source, and the gravel construction vibration will affect the safety of adjacent buildings and the comfort of the residents. When the stroke is 0.8 m, 1.0 m and 1.2 m, respectively, The horizontal safety distance of adjacent buildings is 14m / 18mt / 20m, and the acceptable vibration distance is 24mt / 29mt / 31m.The safe buried depth of buried concrete pipe culvert under the road is 2.4 m and the safety distance of the building level on the embankment slope is 12m.m3) the hammering position is in the right direction when the stroke is 1.0 m. The vibration of plane structure has great influence. The impact effect on pavement structure is the most obvious when used as a plate angle, and the pavement slab is most easily broken, so in the construction process, the impact is usually first broken from the angle of the plate, and then pushed into the plate step by step. Among the four factors that affect the vibration velocity of the pipe culvert, The order of parameter sensitivity from large to small is: horizontal distance between pipeline and vibration source, buried depth of pipe culvert, load position and stroke. Methods such as reducing stroke are used to reduce the vibration effect on adjacent structures.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U418.6

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