水頭降下を伴うフィルターの安定設計

概要

論文の詳細を見る
The optimum design of the filter with head loss is performed using S_<res.> as a parameter of stability, where S_<res.> is an area of distribution of the residual vertical effective normal stress σ_<τ'res>. in a critical state. The following three types of distributions of coefficient of permeability k are investigated precisely here : (1) Two-layer varying type, (2) locally linearly varying type, (3) locally bi-hyperbolically varying type and (4) locally hyperbolically varying type, which are considered to be able to represent almost all distributions of k of a filter. The filter is approximated to a 1000-layered system systematically and S_<res.> of the filter is analysed using the computer program CRIT1 (Critical State Calculation Program for Seepage Failure of a Multi-Layered Ground). In this paper, the various cases of k_r (>1.0) are investigated systematically, where k_r is the ratio of coefficients of permeability at the top and the bottom of a filter. The following results are then obtained : (1) For a given value of k_r, the two-layered system : [numerical formula] is the most stable against seepage failure, where [numerical formula] is the ratio of lengths of the upper and the lower strata of the two-layered system. The superscript * represents the value of the most stable filter. (2) l_r^* increases from 1.0+0 to infinity (l_1^* decreases from 1/2L-0 to 0.0+0), as k_r increases from 1.0+0 to infinity, where L is the total length of the most stable filter. That is to say, the two layer varying point of the most stable filter is descending from the middle to the bottom of the filter, as k_r increases from 1.0+0 to infinity. (3) [numerical formula] is increasing from 0.0+0 to 1.0-0,as k_r increases from 1.0+0 to infinity, where S_<res. max> is the value of S_<res.> of the most stable filter. S_<res. max> is represented as : [numerical formula] (4) k_<av>^* is increasing from 1.0+0 to infinity, as k_r increases from 1.0+0 to infinity, where k_<av>^* is the average coefficient of permeability of the most stable filter and k_l is the coefficient of permeability at the bottom of the filter. k_<av>^* is represented as : [numerical formula].
神戸大学の論文

水頭降下を伴うフィルターの安定設計

スポンサーリンク

概要

著者

関連論文

スポンサーリンク