地下洞室围岩力学参数分区反演方法

Parameters Zoning Back Analysis of Surrounding Rock Mass Underground Caverns

地下工程开挖后,受开挖卸荷、爆破振动及其它施工影响,在围岩中形成一定范围的扰动区。在对其围岩力学参数进行反演时,有必要考虑不同区域的差异。依据损伤程度不同可以将围岩划分为若干力学参数不同的区域,提出了地下洞室围岩分区反演方法。并结合工程实际,利用功果桥水电站地下厂房某断面位移监测数据,对其围岩力学参数进行了分区反演,对反演所得参数进行有限元正算,所得监测点的位移与实测值误差在7%以内,证明了围岩分区方法的可行性与工程适用性。

When an underground engineering opening is excavated,a zone of disturbance in the surrounding rock mass will be formed due to the unloading effect,blasting vibration and other construction activities.Different zones might have different influence when the back analysis id performed and this different influence should be considered.Zoning back analysis method for the rock mass design parameters is proposed based on the different degrees of rock mass disturbance in underground caverns.A case of providing the rock mass parameters for Gongguoqiao Hydraulic Electricity project is presented in this paper.The cross sectional construction monitoring for the underground rock cavern was used for the back analysis.The back calculated rock parameters were used in the finite element analysis.It is concluded that the deformations of the calculated are within 7% of the observed values.