岩体风化卸荷数值判别

Numerical Discrimination of Weathering and Unloading of Rock Mass

风化作用和卸荷作用都会导致岩体破碎。在探硐腰线上测试岩体的纵波速度和岩石的回弹值,并对测得的纵波速度和回弹值分别进行聚类分析,分成不同的数据组。根据风化与卸荷的本质特征,无论岩体风化还是卸荷,其纵波速度都存在级差;但风化岩体回弹值存在级差,卸荷岩体回弹值不存在级差。利用玻尔兹曼函数数学模型,通过拟合计算分析纵波速度和回弹值,对岩体风化与卸荷进行数值判别,并进一步定量划分风化带与卸荷带,确定带的界线。实例应用结果表明:该数值判别方法操作简易,能科学客观地判别风化与卸荷,精确确定风化带与卸荷带的界线,定量解决工程地质问题。

Water resources and hydropower projects often involve rock mass foundation and rock slope.Weathering and unloading can lead to rock disintegration.The impact on construction work is remarkable.The P-wave velocity of rock mass and the rebound value of rock are measured along the exploratory waist line,and then they are clustered and analyzed respectively,vand further are divided into different data groups.According to the different essential characteristics of weathering and unloading,vits P-wave velocity has gradient difference,no matter it is weathered or unloaded;however,the rebound value has a gradient difference only in weathered rock mass,but not in unloaded rock mass.Using the mathematical model of Boltzmann function,vthe authors analyzed the longitudinal wave velocity and rebound value by fitting calculation,made a numerical discrimination on weathering and unloading of rock mass,and further quantitatively divided the weathering zone and unloading zone,and determine their boundaries.The application results show that the numerical discrimination method is easy to operate,vcan scientifically and objectively distinguish the weathering and unloading,vcan accurately determine the boundaries of the weathering belt or the unloading zone,vand can solve engineering geology problems quantitatively.