关键词: 水泥土锚索, 群锚效应, 群锚效应位移系数

Abstract: Large diameter soil-cement anchor cables are increasingly used in the excavations in recent years. However the anchor interval is still designed according to conventional small diameter ones which use cement mortar or cement slurry as anchorage body. Based on an excavation engineering case, the field single anchor and anchor group pulling tests are conducted. Meanwhile, 3D numerical models are developed to simulate field tests. In this paper, the effects of group large diameter soil-cement anchor cables are studied and the displacement coefficients of anchor group effects are presented. The displacement coefficient of allowable anchor group effect is also given according to the current technical code. Influence of the anchor diameter and the anchorage body material on anchor group effect is investigated. It is shown that when the other parameters keep the same, the greater the difference between the stiffness of the anchorage body and the soil, the more obviours anchor group effect, while the greater the minimum interval of anchors are required to reach the allowable displacement coefficient of anchor group effect. The interval of the conventional small diameter cement mortar anchors should not be less than 10D (D is the diameter of the anchor), and the large diameter cement soil anchors should be not less than 6D.

Key words: soil-cement anchor cables, group cables anchor effect, displacement coefficient of group cables anchor effect