RAPID: Confirmation of Structural Dynamics Concepts for Urban Structures Subjected to Adjacent Construction Blasting

该项目提供辅助仪器，以提高建筑爆破振动控制的最新水平，目的是降低城市建筑和设施的建设成本。它利用对纽约市建筑工地高频爆炸诱发激励的建筑反应进行持续测量。额外的仪器将被用来对激励和响应运动进行时间关联，并测量施工法规不要求的其他响应。这种辅助仪器的部署实现的测量将被用来检验这样的假设，即城市结构没有像通常假设的那样受到严重干扰，因此可以安全地减少振动控制。在人口密集的城市地区，古老的和现代的高层建筑可以共存于同一街区。进行岩石挖掘的项目业主和承包商面临着针对被指定为历史建筑、地标建筑或脆弱和需要维修的旧建筑的有限振动限制。对于爆破工程来说，如果只有一座建筑物被认为“容易”从振动中产生表面裂缝，就会严重限制允许的振动极限并限制岩石清除效率，从而降低整体生产率并延长工程的工期。所有这些负面的建筑后果可能会不必要地增加建筑成本。潜在的经济效益是巨大的。仅在纽约市，目前超过170亿美元的交通项目涉及挖掘和在岩石中挖掘隧道的施工爆破。需要进行与时间相关的岩石激励和结构响应测量，以促进对城市结构对高频激励的响应的了解。沿结构的这些测量的时间相关性将允许在计算导致表面开裂的建筑应变时提高准确性，该建筑应变是法规控制的目标。目前的法规和理解是基于对住宅1-2层独户结构在受到低频激励时的反应的测量。在高频地震动激励下，通过反应谱分析将这些观测结果推广到更高的结构上还需要验证。地震工程学、爆炸防护设计和结构动力学中开发的基于激励频率和应变的分析技术应该适用于这些城市情况；然而，由于难以找到完整的试验场，尚未进行测量验证。这个网站和这些工具提供了这个机会。

This project provides supplementary instrumentation to advance the state-of-the-art of construction blast vibration control, with the objective of reducing the cost of constructing urban buildings and facilities. It leverages ongoing measurements of building response to high frequency, blast induced excitation at a construction site in New York City. The additional instruments will be used to time correlate excitation and response motions, and to measure additional responses not required by construction regulations. Measurements enabled by this deployment of supplemental instruments will be used to test the hypothesis that urban structures are not perturbed as greatly as typically assumed, and thus vibration controls may be safely reduced. In dense urban areas old and modern high-rise buildings can coexist on the same street block. Project owners and contractors performing rock excavation are faced with restrictive vibration limits targeted for older buildings designated as historic, "Landmark", or fragile and in need of repair. For blasting projects, the presence of a single building perceived as "vulnerable" to cosmetic cracking from vibrations can severely restrict allowable vibration limits and constrain rock removal efficiency, thereby lowering overall productivity and extending the duration of the project. All of these negative construction consequences may unnecessarily increase construction costs. The potential economic benefit is large. In New York City alone over $17 billion in current transit projects involve construction blasting for excavations and tunneling in rock.Time correlated rock excitation and structure response measurements are needed to advance the understanding of the response of urban structures to high frequency excitation. Time correlation of these measurements along a structure will allow increased accuracy in the calculation of building strains that are responsible for cosmetic cracking, the object of control by regulation. Current regulations and understanding are based upon measurements of the response of residential, 1 to 2 story single family structures when subjected lower frequency excitation. Extension of these observations by response spectrum analysis to taller structures when excited by higher frequency ground motions needs to be validated. Excitation frequency and strain based analytical techniques developed in Earthquake Engineering, Blast Protective Design, and Structural Dynamics should be applicable to these urban situations; however, validation by measurement has not occurred because of the difficulty of finding full-scale test sites. This site and these instruments provide that opportunity.