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

RAPID：确认邻近建筑爆破的城市结构的结构动力学概念

• 批准号: 1445381
• 负责人: Charles Dowding
• 金额: $ 2.4万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1445381&HistoricalAwards=false
• 关键词: RAPID; Confirmation; Structural; Dynamics; Concepts

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.

该项目提供了辅助仪器，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物和设施的建造成本。 它利用了正在进行的测量，在纽约市的一个建筑工地的高频，爆炸引起的激励的建筑物的反应。 额外的仪器将用于时间相关的激励和响应运动，并测量额外的响应不要求的建设条例。 这种部署的补充仪器启用的测量将被用来测试的假设，即城市结构的扰动不像通常假设的那样大，因此可以安全地减少振动控制。 在人口密集的城市地区，古老和现代的高层建筑可以共存于同一街区。 进行岩石开挖的项目业主和承包商面临着针对被指定为历史性建筑、“地标”建筑或脆弱建筑以及需要维修的旧建筑的限制性振动限制。 对于爆破项目，存在被视为“易受”振动引起的表面裂纹的单一建筑物，这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项目的持续时间。 所有这些不利的建筑后果可能不必要地增加建筑成本。 潜在的经济效益很大。 仅在纽约市，目前超过170亿美元的交通项目涉及岩石中开挖和隧道的施工爆破，需要时间相关的岩石激励和结构响应测量来促进对城市结构对高频激励的响应的理解。 沿着结构的这些测量的时间相关性将允许增加建筑物应变的计算的准确性，所述建筑物应变是造成外观开裂的原因，外观开裂是通过法规控制的目标。 当前的法规和理解是基于对住宅、1至2层单户结构在受到低频激励时的响应的测量。 这些观测结果的扩展反应谱分析时，较高的结构，需要进行验证。 在地震工程、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适用于这些城市情况;然而，由于难以找到全尺寸试验场地，尚未通过测量进行验证。 这个网站和这些工具提供了这个机会。