关于pore water pressure线的问题
pore water pressure线是什么意思呢? 其下部的土体是采用天然重度还饱合重度呢? As discussed in the Limit Equilibrium Fundamentals Chapter, SLOPE/W isformulated on the basis of total forces. The unit weight consequently needs to be
specified as the total unit weight.
SLOPE/W allows for a separate unit weight above the water table, but use of this
parameter is seldom necessary.
First of all there is the capillary zone where S is 100% and the unit
weight therefore is the same above and below the water table in the capillary zone.
Secondly, factor of safety calculations are not very sensitive to the unit weight. If
the slice weight increases, the gravitational driving force increases, but the shear
resistance also increases because of a higher normal at the slice base, and vise
versa. Therefore, defining different unit weights above and below the water table
usually has little effect on the resulting factor of safety.
一句话,安全系数对重度不敏感。 补充说明:用水位线确定孔隙水压力是比较常用的方法。通过这种方法,SLOPE/W计算土条底部中心到水位线的竖直距离,乘以水的单位重度即是土条底部的孔隙水压力值。
[ 本帖最后由 basara 于 2007-9-27 17:39 编辑 ] 明白了,谢谢:kiss: 这种方法对安全系数虽然影响不大,但对于锚固力的影响应该存在。 孔隙水压力线,就是浸润线。其下土体应该采用饱和重度吧. 无论哪种重读,数学计算结果都是一样的. 个人感觉影响还蛮大的。从理论上说,浸润线以下的土体容重取天然容重还是饱和容重,要看扬压力的组成。如果扬压力只是渗透体积力,那么容重应该取饱和容重;如果扬压力包含渗透体积力+浮托力,那么容重应该取天然容重。 最主要对与非饱和土浸水的话 浸润线周围的容重怎么办呢 这样的好贴顶上去这样的好贴顶上去这样的好贴顶上去这样的好贴顶上去 thsnks for your discussions and answers!! thsnks for your discussions and answers!! 回答让人不是很清楚啊 cavingao 发表于 2008-7-18 11:03
孔隙水压力线,就是浸润线。其下土体应该采用饱和重度吧.
我想问在计算好渗流以后怎样在渗流的基础上计算稳定? 用户指南说了在稳定分钟中, 安全系数对容重不敏感。所以定义水上和水下两个容重对于安全系数计算的结果影响很小。详见用户指南P94
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