岩体体积节理数表征岩体完整系数的结构面类别修正研究

Study of correction of the structural plane category based on the rock mass integrity coefficient characterized by the volumetric joint count

岩体完整性是评价工程岩体稳定性的重要指标之一。众多研究结果表明,岩体完整性系数Kv能比较全面地体现岩体的完整性,但其测试难度高,且不利于现场测试工作的频繁开展,需要一种更易于测量的指标。基于文献调研及大量工程实测数据,通过研究岩体体积节理数Jv与岩体完整系数Kv的关系,提出了考虑结构面类别的Jv表征Kv的修正方法。修正方法中将结构面划分为5类,明确了结构面性状定性、定量划分依据,并依据实测数据确定了结构面修正系数Jp的取值方法。对比实际工程中的实测Kv值、国标推荐换算得到的Kv值、线性拟合得到的Kv值、修正换算方法得到的Kv值,结果表明,采用修正方法得到的Kv值与实测Kv值的拟合优度更高,绝对残差较国标推荐算法和线性拟合换算结果分别减少了58%和32%,换算准确度更高。这证明了研究提出的岩体体积节理数表征岩体完整系数的结构面类别修正方法在工程应用上是可行的,可以在后续工程中推广使用。

The integrity coefficient of rock mass is one of the important indice to evaluate the stability of engineering rock mass.Extensive research results show that the integrity coefficient Kv can comprehensively represent the integrity of rock mass.However,this parameter is difficult to obtain in frequent field tests.Therefore,a new integrity coefficient that can be easily obtained to represent the rock mass integrity is needed.Based on the literature review and a large number of engineering in situ data,this paper first studies the relationship between the volumetric joint count(Jv)and the integrity coefficient(Kv)of rock mass.A correction method of Jv representing Kv is then put forward considering the type of structural plane.The structural plane is divided into five categories according to the qualitative and quantitative properties of the structural plane.Moreover,the correction coefficient of structural plane,Jp,is determined based on the measured data.Comparing the Kv measured in the practical engineering,the Kv conversed from the international recommended standard value,the Kv conversed by the linear fitting,and the Kv conversed by the proposed correction method,it shows that the goodness-of-fit of the Kv conversed by the correction method and the measured Kv is the highest.The absolute residual reduce 58%and 32%compared to national recommended standard value and the linear fitting conversion,indicating that the conversion accuracy is higher.It is proved that the correction of the structural plane is feasible and exhibits promising application prospect in engineerings.