爆破振动效应的级联复合非线性系统预测方法研究

Predicting the vibrations of large scale structures that are of vital importance to the national economy and the people's livelihood such as large buildings and hydro-structures under the surrounding potential blasting loading in advance is a key problem for establishing and completing the social disaster prevention system and improving the social emergency rescue ability. The existing methods can not completely reflect the nonlinear characteristics of the geomedia and structures responses to vibration or can not predict the structural vibrations in advance. In this work, we seek a new method to predict the vibrations of structures induced by blasting loading occurred in the area surrounding the structures using the nonlinear science theory, model construction, experimental researches and algorithm development. Based on a comprehensive consideration of the different mechanical properties of the geomedia in the different domains and the structure, the geomedia between the blasting source and the structural foundation would be divided into several or multiple domains according to the different mechanical properties. Each domain is described by a nonlinear model and the structure is also described by an independent nonlinear model since the structural mechanical properties are very different from those of the geomedia. A cascade system will be constructed based on the nonlinear models corresponding to the different domain geomedia and the structure to predict the structural vibrations. The identification method of this cascade system will be also developed according to the situ measurement data. The proposed method will break through the limitations and shortages of the analytical method, the linear superposition, the numerical simulation method and the statistical analysis method such as the low precision of the prediction results and inconvenient application in practice. The expected results are to obtain a series of theoretical results that are centered on the nonlinear cascade system to validly predict the structural vibration. The study purpose is to provide a theoretical proof for the safety assessment of structure under blasting loading in the area surrounding the structure. The feasibility of the scientific suppose presented in this work has been preliminarily confirmed by the recent research of the applicant.

大型城市建筑、水工结构等重要基础设施在周边爆炸荷载下振动响应的事前预测是建立和完善社会防灾体系及提高社会应急救援能力的关键。现有方法不能充分体现岩土介质与结构振动响应的非线性特征或不能实现事前预测。应用非线性科学理论，采用理论模型建立、试验研究与算法开发相结合的研究思路，寻求建(构)筑物在周边爆炸荷载下振动响应预测的新方法。在考虑场地中不同区域岩土介质及其与结构本身力学性质差异的基础上，建立不同区域、不同对象的非线性模型，通过这些模型的级联构建复合非线性系统来预测结构的振动响应，提出级联非线性系统的识别方法，以突破解析法、线性叠加法、数值分析法与统计分析法精度低、难于应用的缺点。预期成果为：基于非线性科学理论，形成以级联复合非线性系统为核心的结构振动响应预测的系列理论成果。研究目标：为周边爆炸荷载下结构的安全评价提供理论依据。前期研究成果已证实了科学设想的可行性。

随着国民经济的发展，国家城市化进程的推进，工程爆破技术广泛应用于矿山开采、水利工程、交通工程、拆除工程等领域。在满足工程目的的同时，爆破施工将会产生一系列有害效应，爆破振动作为最突出的有害效应引起了国内外学者的重视，是防灾减灾领域的重要研究课题。针对现有方法不能充分体现岩土介质与结构振动响应非线性特征和不能实现事前完整振动时程预测的问题，本项目采用试验研究、理论分析与算法开发相结合的研究方法，对爆破振动效应的预测开展了深入研究。以Volterra级数类模型为基础，建立了描述爆破振动效应非线性行为的单一和级联复合非线性数学模型；设计了振动测试试验，包括：含伸缩缝的水泥路面人工单点脉冲冲击振动测试试验、混凝土结构模型的爆破振动测试试验、不同爆破参数的岩土爆破振动测试试验，以获取辨识系统所需的最大信息，并分析了爆破振动响应特性；提出了基于多维脉冲响应法的非线性系统辨识方法、利用齐次性解耦各阶核贡献的非线性系统辨识方法、级联复合系统的非线性辨识方法；结合试验数据，建立了一套体现爆破振动效应非线性特性的、可实现事前完整振动时程预测的预测方法。相关研究成果可为爆区周边重大建（构）筑物的安全评估与防护措施的选择提供技术支撑。