【作者】 胡春红；

【导师】 周晶；

【作者基本信息】 大连理工大学 ， 水工结构工程， 2006， 硕士

【摘要】 水下爆炸作用下的结构响应是一个极其复杂的问题，它不但与爆炸的一次齐发药量、爆源与被保护物之间的距离(爆心距)有关，而且与振动的传播介质、承受振动的结构本身的动力特性等有直接关系。迄今为止，水下爆炸的结构响应基本上还是依据实验观测，因其影响因素很多，很难用数值方法进行模拟，国内的研究也几乎为空白。受研究手段和分析方法的限制，无论在深度还是广度上都显得较为肤浅和粗糙。而随着水下爆炸在工业与民用建设上的广泛应用，开展水下爆炸对结构响应影响的研究迫在眉睫。 本文以大连新港改扩建二期工程为依托，针对距爆破最近点4#桥墩可能的响应情况进行了研究：首先对水下爆炸过程进行数值模拟，提耳义爆破地震加速度时程，对老化前及老化后的桥墩结构进行动力时程分析、爆破地震谱分析及安全性评价，并对爆破安全判据提出改进建议。主要的工作和成果包括以下几个方面： 1、概述了大连新港改扩建二期工程背景，介绍了水下爆炸的作用机理，列举了国内外对水下爆炸传播过程数值模拟及水下爆炸作用下结构动力响应数值模拟的成果及不足，在总结当前结构在爆破作用下动力响应存在问题的基础上，指出了本文的研究目的和意义。 2、运用LS-DYNA3D程序对不同炸药量和不同场地条件共6种工况下水下炸礁的爆炸过程进行了数值模拟，得出了爆破地震速度、加速度衰减规律，并分析了炸药量、距离、场地条件对爆破地震速度、加速度的影响。 3、在水下爆炸数值模拟的基础上对4#桥墩进行了爆破地震作用下的动力时程分析及爆破地震谱分析，分析了爆破地震作用下桥墩的位移、速度、加速度及应力规律，以及它们与炸药量、场地条件的关系。 4、考虑材料老化，对桥墩进行爆破地震作用下的动力时程分析及爆破地震谱分析，并与未考虑老化的结果进行对比，研究材料老化对爆破地震作用下结构动力响应的影响规律。 5、由爆破安全规程对老化前、后的栈桥分别进行安全性评价，并与数值模拟结果进行对比，对爆破安全判据提出改进建议。更多还原

【Abstract】 Structural Response subjected to underwater blasting is quite a complex question. It is not only relevant to explosive mass, distance between structure and explosive center, but also associates with surrounding medium and structural dynamic characteristics. So far the research about this subject almost has been made by experimental observation, and can’t be simulated accurately due to lots of influence factors. Restricted by research and analysis methods, domestic study is almost none. Along with underwater blasting widely used in industrial and civil architecture, the significance of structural response analysis subjected to it is much more distinct.This paper relies on rebuilding and extending engineering of Dalian New Port, the nearest 4# pier’s possible response was studied. First, the process of underwater blasting was numerically simulated and the blasting acceleration signal was picked up. Then transient analysis, blasting spectrum analysis and safety evaluation of pier (before ageing and after ageing) were performed. At last, some recommendations for safety criterion were proposed. Works and results are mainly as follows.1. The background of rebuilding and extending engineering of Dalian New Port was summarized. Mechanism of underwater blasting action was introduced. The achievements and deficiencies of the numerical simulation were summarized about two aspects: propagation of underwater blasting wave, and its influence on structural dynamic response. Based on the above analysis, the study purpose and meaning of this paper was indicated.2. The simulation of underwater blasting of six cases which have different explosion mass and ground was performed with the aid of LS-DYNA3D. The rules of blasting velocity and acceleration were deduced. Several factors, such as the distance between structure and explosive center, explosive mass and site properties, were also analyzed.3. Transient and spectrum analysis of 4# pier was carried out on the base of the numerical simulation of underwater blasting. The rules of pier’s displacement, velocity, acceleration and stress response were deduced. The relationship of blasting response with explosive mass and site properties was also analyzed.4. Material ageing was induced in the transient and spectrum analysis of pier subjected to underwater explosion. Its influence over the response of pier was discussed.5. Safety evaluation of pier was made according to safe criterion of blasting. Comparing to the numerical results, some recommendations were proposed.更多还原