Abstract: Under the action of wind, ice and other loads, the transmission line tower foundations will inevitably resist large horizontal force, which will lead to an uplift force in foundations. In this paper, the typical geological conditions of the interbedded highly weathered argillaceous sandstone and mudstone encountered underneath the transmission line foundations are presented in the paper and the typical rock samples are collected. After being exposed in natural rainfall for one month, the rock strength of the samples was tested and compared with the rock core samples without the rainfall exposure. Several insitu load tests were also performed on the single rock anchors and the failure mechanisms of the anchor were analyzed. According to the engineering analogy, the effective anchor length of this type of rock mass is analyzed, and the bond strength between the grout and rock of this type of rock mass is obtained. Combined with other similar engineering data, the relationship between the anchor length and the ultimate uplift deformation value of the soft rock mass and the similar stratum structure is analyzed.

Key words: Highly Weathered Sandy Mudstone Interbedded with Mudstone, Singer Anchor, Anchor Length, Broken Soft Rock Mass