Abstract: In order to solve technical problems of external water pressure for highway tunnel,thirty six tests are made under different conditions including different water head height,permeability coefficient,discharge amount and drainage system with own designed apparatus by similar theory.According to test results,discount rule of external water pressure is analysed.Furthermore,some cognitions are also pointed out,which include that the similar relation of water head height is square relation on engineering analogy and composite backfill method is introduced to deal with abundant water cavities around tunnel.

Key words: highway tunnel, external water pressure, discount coefficient, composite backfill

摘要： 针对确定隧道外水压力的技术难题,根据相似理论,利用自行设计的模型试验装置,在不同水头高度、渗透系数、排放量以及排放系统的条件下,进行了36组工况试验。根据试验结果,对外水压力的折减规律进行了研究。分析提出了工程类比应注意水头高度为平方的相似关系,以及对于隧道周边富水洞穴应按"复合回填"的方式进行处治的深入认识。

关键词: 公路隧道, 外水压力, 折减系数, 复合回填