土钉支护中土压力计算

土钉墙柔性面层结构上承受的土压力既不符合传统土压力理论计算适用条件，也没有现有理论可以求解，目前大多根据工程经验确定。基于土钉技术可充分发挥土体自稳性的特点，将上限理论推导出的计算式与实测数据结合起来，得到一土压力计算方法，并应用于一复合土钉墙实例。计算土压力与实测数据相符。分析结果认为，当开挖深度超过土体的自稳高度后，土钉结构上一定承受土压力，其大小与开挖深度、坡角、土层性质、支护结构布置相关。该方法适用于土钉墙、复合土钉墙土压力计算。

New approach for determining earth pressure in soil-nailing technology

The earth pressure on flexible structures in soil-nailing walls is neither in accordance with the preconditions of the traditional pressure theory, nor has suitable theories to apply. The earth pressure thus has to be evaluated by engineering experience. A new method is proposed for evaluation of the earth pressure by combining the upper bound solution with engineering data to show the characteristics in soil nailing so as to allow soil to move and mobilize the soil strength. The new method is applied to a composite wall for validation. The analytical results are found to be in agreement with the actual conditions. The earth pressure exists after the excavation depth exceeds the self-stabilizing height of the soil. Its value is related to the excavation depth, slope angle, soil properties and supporting structural settings. The proposed method is suitable for determining the earth pressure on soil-nailing walls, composite soil-nailing walls.