【摘要】 当前隧道建设过程常面临穿越多元地层的情况，其中处于二元地层中隧道围岩压力的计算方法存在争议：当两种地层地质参数相差较大时，常用的均值法不再适用。在二元地层中，通过研究普氏理论围岩压力计算方法的使用条件，以地层的物理性质为基础，设立计算宽度标量W并基于物理计算模型分析，提出二元地层情况下普氏自然拱的建模方法及改进计算方法，称为修正参数法。通过对实际工程中的案例分析，使用修正参数法和常用取均值法分别与工程实测数据进行对比。结果表明，随着二元地层地质特性差异变大，常见均值法结果与实测值相差越大，数值结果最大相差为15.8%,均值法不适用。提出的修正参数法由于计算参数综合考虑了二元地层特性，适用于各种差异程度的二元地层情况，可为隧道穿越二元地层的围岩压力计算提供参考。更多还原

【Abstract】 At present tunnels are often designed to be located in multiple strata, and there was a controversy over the calculation of tunnel surrounding rock pressure in binary strata: When there was a significant difference in geological parameters between two formations, the commonly used mean method was no longer applicable based on the principle of taking the average value of parameters. By studying the problem of limitations on the use of homogeneous formations in the calculation of surrounding rock pressure using the Poisson’s theory in binary formations, this paper records a modeling method for Poisson’s natural arch in binary formations and improves the calculation formula. Based on the physical properties of the strata, a new calculation width scalar W is named to derive a modified calculation method for the pressure of tunnel surrounding rock in the binary strata, known as the modified parameter method. By analyzing practical engineering cases, the modified parameter method and commonly used mean value method were compared with actual engineering data. The conclusion of the study is that as the differences in geological characteristics of binary strata increase, the difference between the common mean method results and the measured values increases, with the maximum difference of 15.8%. The mean method is no longer applicable. The modified parameter method takes into account the characteristics of binary formations and is suitable for various situations of binary formations. It also provides a reference for the calculation of surrounding rock pressure in the same situation.更多还原