【作者】 张丹；

【导师】 张继春；

【作者基本信息】 西南交通大学 ， 岩土工程， 2008， 博士

【摘要】 爆破地震可导致地质灾害,破坏生态、影响人居环境,而优化爆破参数是改善爆破地震强度分布特征,避免被保护物遭到破坏重要举措。随着爆破作业环境日益复杂,控制爆破地震效应要求提高,设计与施工所依据的理论不得不相应调整,不但有其理论科学性,而且应具有技术可操作性和经济比较优越性。对爆源因素影响爆破振动速度分布特征与频率分布特征其实验研究现状与理论研究现状进行综述,以及将分别由球形药包与条形药包、单药包与药包群爆破所产生的质点振动速度分布特征与频率分布特征已有研究进行比较分析,指出与爆源因素影响质点振动速度分布特征和频率分布特征相关研究存在不足,并对其评价与展望。基于爆破地震实验建立的爆源因素与爆破地震质点振动特征实验关系缺少理论论证,以及影响爆破地震强度分布特征爆源因素不够全面,从控制药量、调整药包形状及其空间状态以及药包群空间分布形式及其与被保护物相互空间关系设计爆破参数,使被保护体处于较弱的爆破震动区域,却更能控制爆破地震效应等相关研究是必要的,提出了爆源因素影响爆破地震强度分布特征研究课题。对任何炸药(同种炸药密度相同,超过极限直径),无论药量多少,其爆轰时均有其恒定的爆轰压力,却质点振动速度及其频率与炸药量存在函数单调关系。依据动量守恒,以及能量、爆炸波应力在径向和时间域上衰减规律,通过炸药爆炸激发的爆炸冲量,爆炸波能量及其应力在传播过程中的力学行为分析,研究爆炸冲击波与膨胀气体力学行为特征,从理论上论证了爆破地震质点振动速度、频率和持续时间与炸药量和爆心距其函数单调性。通过调整药包形状,药包相对空间位置,以改变爆破地震质点振动速度在地表方位分布与梯度分布,依据岩土的粘滞性对爆破地震波传播的阻尼理论与波动学说,辅之以数值分析,研究单药包形状或者药包相对空间位置对爆破地震地表质点振动速度分布特征的影响,获得了药包的形状,爆源相对空间位置与爆破地震强度分布特征相互关系。通过调整药包群空间点阵形式、药包群点阵展布态势、药包数,以改变爆破质点振动速度分布特征,依据在不同粘性传播介质中爆破地震其波动能流衰减规律和动载形成的应力波在均质岩石介质中衰减规律及其爆破地震破坏程度取决于振动强度等因素以及波动能流密度与质点振动速度呈正相关等相关理论,研究药包群爆源因素对爆破振动速度分布特征的影响,探讨药包群同时起爆其爆破地震其波动能流主导方向及其在同方向上振动强度与爆心距相互关系,获得了药包群同时起爆地震强度分布特征,建立了药包群包络面主法线方向与地震强度分布优势方向相干性。基于动载作用下,粘性介质应变滞后于应力,并伴随着波动能量耗损,探讨爆破地震强度对起爆段数收敛的存在性;由相同段别等间隔时间起爆所产生的爆破地震波叠成的综合波谱,推导段数与爆破地震强度相干数学表达式,以及影响爆破地震强度收敛段数因素分析,论证了等分段等间隔时间爆破地震强度对起爆段数存在收敛性,以及间隔时间对收敛段数的影响。更多还原

【Abstract】 Blasting seismic tremors can give rise to geological disaster, destroy the ecological environment, and disturb normal livelihood, while optimizing blasting parameters are an important measure to avoid harming the protected structure and to improve the distribution of blasting vibration intensity. With blasting environment situation getting increasingly complex and the requirement of blasting seismic effects controlling being more demanding, the corresponded theories on designing and construction, accordingly, have to be adjusted so as to be theoretically scientific, technologically operable and economically advantageous.The status quo of both the experimental and the theoretical studies on distribution characteristics of vibration intensity influenced by blasting resource factors is to be presented; then, a comparative analysis between the contribution characteristics of blasting vibration intensity caused by spherical charges and cylindrical charges by oneself, or between single charges and several charges by oneself is to be conducted, from which the limitation of the previous researches is presented, evaluated and forecasted. The existing investigations concerning experimental relationship between blasting resource factors based on experiment and distribution characters of vibration intensity lacks theoretical confirmation; in addition, blasting resource factors, which influence blasting seismic intensity, are not all-round. In views of it, it is necessary to make further researches on distribution character of vibration intensity influenced by blasting resource factors. The present study argues that to locate the protections in the comparatively weak seismic field yet still better control the blasting seismic effect, the blasting parameter is to be devised through controlling charges’ quantity and regulating charges’ shape and spatial state, as well as the spatial relation between spiral lattice form, the charges’ number, the charges’ lattice extension and the subordinate number.No matter how much explosive there is, the detonation pressure of any explosive is constant, because blasting vibration intensity are monotone functions about charges’s quantity. According to the momentum conservation law, and the attenuation law of blasting vibration energy and its pressure with time and distance from explosion center, from the perspective of the radial propagation mechanical behavioral characteristic of the detonation impulse momentum from the explosive, the energy s’ diffusion and loss of explosion wave and its pressure, the behavioral characters of the shock wave and detonation gases are studied, the result of which testifies in theory the function’s monotone between blasting vibration intensity and the explosive quantity and the distance from blasting resource by the theory.Through adjusting charge’s shape, charge’ s relative spatial relations to change the direction distribution character and the gradient distribution character of blasting vibration velocity, the relation between blasting vibration intensity and charge shape , the charge’ s relative spatial relations is examined on the basis of the wave mechanics and the theory to dump blasting seismic wave influenced by propagating medium’ s sticky, complemented by numerical analysis, with the purpose of acquiring the result of the interrelation among charge shape, charge’ s relative spatial relations and the distribution of blasting vibration velocity.Through adjusting blasting parameters such as the charges’ spiral lattice form, the charges’ number and the charges’ lattice extension to change the distribution character of blasting vibration velocity, on the basis of the laws that energy flow of the blasting seismic wave attenuates in different sticky medium, that stress wave attenuates in rock medium under impact load, that the extent of the blasting seismic damage depends on the factors such as blasting vibration velocity, and that energy flow of the blasting seismic wave is monotone functions about blasting vibration velocity, the relation between blasting source factors and the distribution character of blasting vibration velocity is investigated; in addition, the predominant direction of wave energy’s flow and the relation between blasting vibration velocity and the distance from blasting sources are approached. Then, the distribution rule of blasting vibration velocity is drawn, furthermore, the relation between distributions’ predominate orientation of blasting vibration and the envelope in which explosive charges exist, is set up.Based on the exhausted energy theory about various hysteretic loops, that is, strain lags behind stress in stickup under impact load, it is proved that blasting vibration velocity reaches the convergent value with subordinate number rising. The mathematical formula of relations between the subordinate number and blasting vibration intensity is drawn frown the spectrum composed by subordinate blasting vibration velocity increasing with the subordinate number rising under both the equal subordinate conditions and the equal intervals by seismic wave’ s superposition, in order to probe whether it corresponds to the reality that the blasting vibration velocity reaches the convergent value with subordinate number rising. The formula is analyzed by mathematical software, with the aim that the existence of the convergent character is confirmed, and how the delaying time influences the convergent subordinate number are drawn.更多还原