动载扰动下充填节理动力特性及其对应力波传播规律影响研究

The dynamic mechanical behavior of filled rock joints and its influence on stress wave propagation are important bases for dynamic response analysis and safety evaluation of rock mass engineering. In view of the problem that dynamic loading disturbance leads to the strength weakening of filled joints and affects the attenuation of vibration wave, the project intends to study the cumulative damage characteristics of filled joints and its influence on the stress wave propagation by means of laboratory tests, theoretical analysis, and numerical simulation. First of all, experimental studies on the dynamic mechanical behavior of filled joint under dynamic loading disturbance and its factors is to be carried out, and the dynamic strength weakening mechanism of filled joints was clarified. After that, the corresponding relationship between strength weakening, cumulative damage-dynamic parameters was quantified, and the dynamic mechanical characteristics model considering the cumulative damage will be established. Then, based on the proposed dynamic model, the wave prpoagtion through a single filled joint is to be analyzed, and attenuation mechanism of stress wave caused by strength weakening of filled joints is revealed. Finally, by embedding the joint model into the numerical simulation software, the numerical simulation for stress wave propagation in rock mass involving a set or multiple sets of filled joint will be conducted, and the influence of joint characteristics on stress wave propagation and ground vibration response is clarified. The research results can provide important theoretical basis and technical support for the safety evaluation of blasting excavation in rock mass site. Meanwhile, the results are also of great significance to develop the theory of stress wave propagation in jointed rock mass.

充填节理的动力特性及其对应力波传播规律的影响是岩体工程动力响应分析和安全性评价的重要依据。针对动载扰动导致充填节理产生强度劣化并影响振动波的衰减等问题，本项目拟采用室内试验、理论分析及数值模拟相结合的方法对充填节理累积损伤特性及其对应力波传播规律的影响展开研究。通过室内试验研究动载扰动前后充填节理动力特性及其主控因素，阐明充填节理动力强度劣化机理，量化强度劣化-累积损伤-动力参数的对应关系，建立充填节理累积损伤动力模型。在此基础上，理论解析应力波在充填节理中的传播规律，揭示充填节理强度劣化对应力波的衰减机制。利用构建的累积损伤动力模型，开展复杂分布的节理岩体中应力波传播的数值模拟研究，阐明节理特性对应力波传播以及地表振动响应的影响规律。研究成果对岩体场地爆破开挖设计、施工及安全性评价提供了理论支撑，同时丰富了应力波在岩体中传播理论，具有重要的科学研究与工程应用价值。

节理的动态力学特性及其对应力波传播规律的影响是岩体工程响应和安全性评价的重要依据。针对动载扰动导致充填节理产生强度劣化并影响振动波的衰减等问题，本项目通过室内试验、理论分析和数值模拟相结合的方法对充填节理的静动力学特性、多次冲击作用下的累积损伤动力特性及其对应力波传播规律的影响展开了研究。首先，采用霍布金森压杆（SHPB）和压缩试验装置实验分析了不同充填材料以及不同充填厚度的充填节理岩样静动态力学特性及其影响因素。其次，对充填节理在累积动荷载扰动下的强度弱化展开实验研究，阐明充填节理动强度衰减机理，量化了强度损失与累积损伤的关系，并建立考虑累积损伤弱化效应的黏弹性节理分析模型。继而理论分析了应力波与充填节理的相互作用，建立了波传播方程，揭示充填节理强度弱化对应力波透反射特性的影响规律。通过引入品质因子及黏弹性等效模型，理论方面分析了含结构面的非线性岩体中的应力波传播规律。然后，采用PFC建立了充填节理压缩特性的细观数值模型，并对复杂情况下的节理岩样压缩特性进行了模拟，阐明了含充填节理岩样的压缩损伤演化规律及破坏机制。宏观模拟方面，采用UDEC对应力波在含复杂节理岩体中的传播进行数值模拟研究，揭示充填节理特性对波传播以及地表振动响应的影响机制。最后，对爆破荷载作用下的工程岩体振动响应进行模拟计算及分析。研究成果对岩体场地爆破开挖设计施工、岩质边坡工程及地下洞室的安全性评价具有重要的工程应用价值，同时对发展应力波在岩体中的传播理论也具有显著意义。