三向压力盒的成功研制为深部软岩巷道围岩的地应力测量提供了一种新的方法。然而，三向压力盒的使用会与土压力盒的使用产生类似的问题，即压力盒埋设必然会改变介质的初始应力场，引起应力集中和应力重分布现象，导致压力盒实测结果与介质初始应力场关系的重大不确定性。为了解三向压力盒嵌入对介质初始应力场的扰动规律及其自身的应力感知特性，采用数值软件模拟三向压力盒嵌入介质后的应力场分布。考虑不同应力状态和弹性模量比（三向压力盒和介质）条件下介质主应力场的重分布特征以及三向压力盒的各部件的受力特性，揭示初始应力状态和弹性模量比对介质主应力场和三向压力盒受力特性的影响规律。在此基础上，根据三向压力盒承载面的实测应力随介质的初始应力状态和弹性模量比的变化规律，建立三向压力盒实测应力与介质初始应力状态以及弹性模量比的数学关系。良好的拟合结果表明，提出的数学表达式能够反映三向压力盒实测应力与介质初始应力状态的关系。

The three-dimensional pressure cell (3DPC) provides a novel method to measure the geostress of the deep soft surrounding rock. However, due to the installation of 3DPC, the distribution of initial stress field of the surrounding medium is inevitably changed, and then the redistributed and concentrated stress result in the significant indetermination of the relationship between the measured stress by 3DPC and the initial stress field of surrounding rock. The above problem also exists in the applications of earth pressure cell. In order to study the embedding effect of 3DPC on the initial stress field of medium and stress properties measured by 3DPC, numerical software is employed to simulate the installation process and the stress redistribution of the medium. Under different conditions of stress state and the elastic modulus ratio of 3DPC to surrounding medium, the characteristics of the principal stress redistribution field and the stress distribution of each part of 3DPC are analyzed. Moreover, the analytical models are established on the basis of the variations of measured stress by 3DPC with different initial stress state and modulus ratio. The well-fitted results show that the proposed theoretical expressions are validated to reflect the relationship between the 3DPC measured stress and the initial stress of the surrounding medium.