高压气体驱动下的岩体裂纹扩展规律和实用技术研究

The technique of high-pressure-gas generation and its mechanism of rock fracturing will be studied in the current research, which will contribute to improve both the efficiency and effect of a practical application in rock excavation: the carbon dioxide (CO2) fracturing. First, the temperature and pressure of liquid CO2 are managed to be measured after it is gasified in a tube by heating. The equation of state for gas pressure will be worked out and its influencing factors will be analyzed. Then, a series of model and field tests will be carried out to investigate the fracturing process driven by high-pressure-gas in concrete material and rock mass, respectively. On this basis, the key factors which affect the dimension and orientation of gas driven cracks will be explored thoroughly by theoretical analysis and numerical simulations. The high-pressure-gas promotes crack growth and, in turn, the crack growth provides new flow path for high-pressure-gas. This mutual promotion and connection constitutes the theory of crack growth driven by high-pressure-gas, which will provide guidance for the implementation of CO2 fracturing technique.

从二氧化碳(CO2)致裂技术在岩体破碎开挖领域的实际应用需求出发，解决高压气体的产生和致裂机制，提高气体的致裂效果和效率。首先进行储液管内的液态CO2加热气化后的动态温度和压力变化测试，提出气体压力的状态方程，分析高压气体爆炸压力的影响因素。然后进行高压气体致裂混凝土材料和边坡岩体的模型和现场实验，并对气体驱动下的裂纹产生和扩展规律进行理论和数值计算分析，归纳影响岩体裂纹扩展长度、方向等特征的各种因素，研究高压气体对裂纹扩展的驱动作用和裂纹扩展创造的新通道对气体流动和压力分布的影响，建立高压气体作用下的裂纹产生和气体驱动下的裂纹扩展规律的基本理论，为气体致裂的实际应用提供理论基础和技术指导。

研究工作从CO2致裂技术在岩体开挖领域的实际需求出发，解决CO2高压气体的产生和致裂机制，揭示CO2致裂技术在减小岩体损伤和振动方面的技术优势。首先，进行了致裂管内的CO2加热相变后的动态压力测试，得到了致裂管内气体压力的量值和变化规律，提出了致裂管内气体压力的计算方法并分析了高压气体压力的影响因素。然后，进行了高压气体致裂混凝土材料和边坡岩体的模型和现场试验，以此为基础对气体驱动下的裂纹扩展规律进行理论推导和数值计算分析，研究了高压气体的存在对裂纹扩展和分布的影响，建立了气体作用下的岩体裂纹扩展计算和分析模型，为气体致裂的实际应用提供了理论基础和技术支持。