擋土牆排水設施之排水功效

Draining Effect of Retaining Wall Drainage Facility

黃漢誠(Han-Chen Huang) ； 陳主惠(Chu-Hui Chen) ； 譚義績(Yih-Chi Tan)

《中華水土保持學報》 30卷3期 (1999/09) Pp. 167-179

https://doi.org/10.29417/JCSWC.199909_30(3).0001

摘要

本研究理論根據水份及土壤質量守恆方程式，並配合三維度、時變性、土壤及水份有壓縮性、研究區域內存在點源及點匯等假設來形成飽和與非飽和地層之地水流動，並以孔隙介質飽和與非飽和水流有限元素法數值模式（FEMWATER）爲計算核心；模擬中針對不同之排水設施在全區飽和的初始條件、相同降雨強度下，擋土牆背部水位之升降情形做出討論，結果顯示設置洩水孔搭配貼牆式排水層、橫向排水管搭配貼牆式排水層及橫向排水管搭配水平式排水層等排水設施，對牆背水位的減低及水力梯度的增加有不錯的效果；在排水層的設置上，當牆背水位甚高時，鄰近牆背處之水位的降低及水力梯度的增加以貼牆式排水層的效果較佳，水平式排水層能均勻降低鄰近牆背處之水位，並且排出較多之水份，但由水力梯度的觀點看來，在相同外在條件下仍較貼牆式排水層弱；加高水平式排水層高度對牆背水位的減低效益不大，但藉此所匯流出之水份多於厚度較薄之水平式排水層。

關鍵字

洩水孔 ； 排水層

並列摘要

The aim of the present research is to study the influence of retaining wall drainage facility on draining. We used conservation of water and soil mass as the governing equation. The theory is based on the following assumptions: three dimensions, time variability, compressible soil, compressible water, and multiple sources and sinks. We have simulated the groundwater flow in saturated and unsaturated soil layer by FEMWATER, and used a Groundwater Modeling System as an operating interface. We have analyzed the change of wall-back groundwater level during the same initial condition, same rainfall intensity, but different drainage facilities. The results showed that three kinds of drainage facilities, namely, weep hole with vertical draining blanket, transverse draining pipe with vertical draining blanket, transverse draining pipe with horizontal draining blanket, can all reduce wall-back waterlevel quite well. When setting the draining blanket, if the wall-back waterlevel is quite high, vertical draining blanket is the best effort to reduce the waterlevel. Although the horizontal draining blanket can drain more water, it is not quite stable for the wall. By Comparing different thickness as of draining blanket: We conclude that the increasein the height of the horizontal draining blanket cannot help much in reducing the wall-back waterlevel, though, it can drain more water than a thinner draining blanket.

並列關鍵字

weep bole ； draining blanket