泥石流危害桥隧工程承灾链特征与工程易损度动态评价方法研究

A consensus has been widely reached that the debris flow could cause enormous harm. At present, although there are abundant achievements for debris flow's prevention and mitigation, it's still not effective in curbing its tremendous devastation towards bridge/tunnel engineering. An important reason is that the mechanism of joint counter-disaster hasn't been realized, in which the counter-measures designed in the risk-management and the bridge/tunnel engineering designed in the civil-engineering's criterion respectively serve as the hazard-affected body. Therefore, a new concept for disaster prevention and mitigation was put forward, in which the hazard-affected chain combined with counter-measures and infrastructure jointly counter the disaster, planning to verify the debris flow's regional triggering environment and its hazard characteristics. Based on the hazard-affected chain, this project would summarize and extract the hazard mode and its changing pattern for the debris flow's damage on bridge/tunnel engineering with the case analysis method. Through studying the legitimate matching relation for the hazard-affected chain, the joint counter-disaster's action mechanism would be revealed by conducting the immovable bed normal model experiment. For the purpose of quantificational assessment on the effect of disaster prevention, the risk management design for geological hazard's counter measures and the civil engineering's criterion design for infrastructure would be bridged. On the basis of the engineering vulnerability's concept defined by the applicant, a new dynamic engineering vulnerability assessment method in consideration of the functional loss and structural damage would be established. The vulnerability that severs for the governmental macro-disaster management planning in the economic scale would be feasibly extended, to the engineering vulnerability that could be directly applied in the field of designing and constructing for the departments of engineering and administration.

泥石流危害巨大已为共识，目前研究成果丰富，但仍无法有效遏制其对桥隧工程巨大破坏性。重要原因之一是：基于风险设计泥石流治理措施第一承灾体，与基于土木工程标准设计的基础设施（如桥隧工程）第二承灾体，共同承灾机理没有被认识到。为此，本项目提出承灾链（治理措施与基础实施）共同承灾的防灾减灾新理念，拟首先探明我国泥石流孕灾环境区域特性与致灾特点，采用案例分析法，总结提炼基于承灾链的泥石流危害桥隧工程致灾模式及其变化特点，并开展定床正态模型槽试验，研究承灾链共同承灾的合理匹配关系，揭示泥石流危害桥隧工程致灾机理。为量化评价新理念防灾效果，搭建地质灾害治理风险设计与基础设施土木工程标准设计之间的桥梁，基于申请人提出的工程易损性概念，建立考虑功能损失与结构损坏的工程易损性动态评价新方法，将政府宏观治灾规划的经济价值尺度衡量的易损性，延伸到直接应用于工程、管理部门的设计与施工的工程易损性。

山地地区易发泥石流灾害，使桥隧工程等道路、铁路基础设施面临巨大危险。针对泥石流致灾体风险性与桥隧工程承灾体易损性的研究一直是国内外防灾减灾研究的热点问题。立项项目围绕以上问题，进一步针对泥石流孕灾环境、承灾链作用机理、防治措施与桥隧工程的合理匹配关系以及工程易损性等核心内容开展研究，为揭示泥石流危害桥隧工程致灾机理、量化评价防灾效果与桥隧工程受灾后的服役性能提供了理论基础。取得主要成果如下：（1）项目完成了低山丘陵地区19条及活动断裂区26条泥石流沟道的调查工，据此总结提炼了低山丘陵地区“台风—暴雨—泥石流”与活动断裂区“地震—暴雨—泥石流”的孕灾环境特征，发现并揭示了竹林等浅根系植对泥石流“先抑灾后致灾”的特点特征及其机制，并分别提出了基于博弈论组合赋权、模糊神经网络及故障树的泥石流危险度评价方法；（2）构建了泥石流致灾体起动、流动模型，通过案例分析，概化了泥石流危害桥隧工程的承灾链，分析了承灾链相互作用机理，并基于承灾链作用的分析结果，对防治工程措施进行了合理优化；（3）围绕低山丘陵地区与活动断裂区4条泥石流沟道治理项目的长期跟踪，验证了防治措施与桥隧工程间合理匹配关系的存在，通过对泥石流致灾模式影响因素分析、防治工程结构的合理优化，研究了防治措施与桥隧工程间合理匹配关系对泥石流防灾减灾效果的影响；（4）在泥石流工程易损性评价体系中补充了泥石流治理措施的指标参数，合理完善了泥石流工程易损性理念，形成了兼顾“结构损毁”与“功能损失”的桥隧工程易损性评价体系。项目取得的成果总体围绕泥石流承灾链关键环节，做出了全链式突破，丰富了泥石流孕灾环境特征及危险性分析方法、完善了工程易损性理念与评价体系、并基于承灾链优化了泥石流防治工程设计。依托项目开展，形成成果共计发表论文15篇，参加国际会议2次，国家发明与实用专利各1项，并培养硕士研究生2人，博士研究生1人。