A new concept called the transmission ratio of ground volume loss (TRGVL) is proposed to describe the variation law of ground volume loss with depth above the tunnel. Based on the developed Gaussian function, the formula for TRGVL is deduced. Further, the first-order derivative of TRGVL is presented to evaluate the dilation and compression degree of the soil at any depth above the tunnel. A total of 15 cases, involving eight field project cases and seven model test cases, are investigated to validate rationality of the proposed formula. The results of field projects and model test cases indicate variation in TRGVL presents four forms. By analysing the volumetric deformation of the soil above the tunnel, formation mechanism of the each form of TRGVL is revealed. Finally, the evolution of the four forms of TRGVL is used to evaluate the disturbance degree of the soil above the tunnel.

提出了一种称为地体积损失传输比（TRGVL）的新概念来描述地体积损失随隧道上方深度的变化规律。基于开发的高斯函数，推导出TRGVL的公式。此外，还提出了TRGVL的一阶导数来评估隧道上方任意深度土壤的膨胀和压缩程度。共调查了15个案例，涉及8个现场项目案例和7个模型测试案例，以验证所提出公式的合理性。现场项目和模型测试案例的结果表明，TRGVL 的变异呈现四种形式。通过分析隧道上方土体的体积变形，揭示了各种形式的TRGVL的形成机制。最后，