The backfilling of underground stopes in mines has become common practice in the mining industry as it increases the stability of mine excavations and reduces environmental problems. The backfilling process involves several technical aspects that must be assessed to ensure that the backfilling objectives are achieved. The horizontal stress exerted by backfill on excavation walls must be estimated accurately to avoid the failure of mine pillars. The analytical Marston method is often used for evaluating this stress as it takes into consideration an earth pressure coefficient (K) that is dependent on the geotechnical properties of the backfill. This paper demonstrates that the accuracy of the Marston method for predicting horizontal earth pressure would be improved by using K values that are determined as a function of backfill geotechnical parameters and also excavation geometry. Both components vary inevitably from one backfilled site to another. A methodology is developed to adjust the K value to be a function of these parameters for its application within the Marston analytical method thereby providing a more accurate prediction of earth pressure. Based on various geometric and geomechanical parameters, two graphs are developed to evaluate proper earth pressure values. These graphs can be used for estimating more accurate K values that are based on the characteristics of the stope and the backfill material.

中文翻译：

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基于采场回填的地质力学和几何参数的土压力系数

矿山地下采场的回填已成为采矿行业的普遍做法，因为它可以提高矿山开挖的稳定性并减少环境问题。回填过程涉及几个技术方面，必须对其进行评估以确保实现回填目标。回填对开挖墙施加的水平应力必须准确估算，以避免矿柱破裂。由于考虑了土压力系数（K），该方法通常使用解析Marston方法评估该应力，该土压力系数（K）取决于回填土的岩土特性。本文表明，使用K可以提高Marston方法预测水平土压力的准确性。根据回填岩土参数以及开挖几何形状确定的值。从一个回填站点到另一个回填站点，这两个组件不可避免地会有所不同。开发了一种方法来将K值调整为这些参数的函数，以便在Marston分析方法中将其应用，从而提供对土压力的更准确预测。基于各种几何和地质力学参数，开发了两个图形来评估适当的土压力值。这些图可用于根据采场和回填材料的特性估算更准确的K值。