论文部分内容阅读
一、前言 葛洲坝水利枢纽第一期工程基岩为白垩系下统陆相红色碎屑岩、粘土质粉砂岩夹中细粒砂岩及中细粒砂岩夹粘土质粉砂岩,岩层走向北东20～40度,倾角4～8度,倾向左岸偏向下游,并有许多粘土质岩类的软弱夹层.其中粉砂岩和粘土质粉砂岩(以下统称粉砂岩)比较软弱.按有的规范规定,基岩的承载能力,以室内岩块单轴极限抗压强度的1/5～1/25来选取,软岩取1/5～1/10.据此,该工程设计中,粉砂岩取湿抗压强度100公斤/厘米~2的1/10,即10公斤/厘米~2为允许承载能力.但有些建筑物如船闸边墙基础,最大压应力达17公斤/厘米~2,远超过这一允许承载能力.则应采取增加钢筋混凝土的工程措施.因此,如何合理确定其允许承载能力,是一重要的工程课题. 以室内岩块抗压强度用折减系数来确定基岩的允许承载能力是一种经验方法.实际
I. INTRODUCTION The bedrock of the first phase of the Gezhouba Water Conservancy Project is the Cretaceous Lower Terrestrial continental clastic rock, clayey siltstone sandstone, fine-grained sandstone, and medium fine-grained sandstone clayey siltstone. 40 degrees, dip 4 to 8 degrees, tend to the left bank towards the downstream, and there are many weak interlayers of clay rocks, of which siltstone and clay siltstone (hereinafter referred to as siltstone) is relatively weak. According to some regulations, the bedrock The load capacity is selected from 1/5 to 1/25 of the uniaxial ultimate compressive strength of the indoor rock, and soft rock takes 1/5 to 1/10. Accordingly, in the engineering design, the siltstone is wet and compressive. One tenth of the intensity of 100 kg/cm~2, ie 10 kg/cm~2, is the permissible carrying capacity. However, some buildings such as the ship’s side wall foundation have a maximum compressive stress of 17 kg/cm~2, far exceeding this allowance. Bearing capacity should be taken to increase reinforced concrete engineering measures. Therefore, how to reasonably determine its allowable bearing capacity is an important engineering issue. The use of the reduction factor of indoor rock compressive strength to determine the allowable bearing capacity of bedrock is An empirical method. Actual