英文篇名
HYDROGEOLOGICAL INVESTIGATION AND ANALYSIS OF TRANSBASIN DIVERSION TUNNEL OF TSENGWEN RESERVOIR
作者
楊豐榮、顧承宇、譚志豪、許世孟、鍾明劍
關鍵字
隧道工程、水文地質調查、隧道湧水、地下水、三維數值分析
摘要
台灣地區因雨量充沛,且位於歐亞板塊與菲律賓板塊交接處,活躍的造山運動造成岩層之破碎度高而節理發達,故地表水易沿地質弱面滲入岩層,以致岩盤中之地下水儲量豐富。近年來山岳隧道之開挖經驗顯示,穿過高山地形之長隧道因水文地質條件十分複雜,隧道施工時除因大量湧水造成施工困難外,亦常因地下水流失引發鄰近區域環境水文地質之爭議。本文以曾文越引隧道工程為例,分別針對:(1) 山岳隧道工程之水文地質現地試驗技術、(2) 結合地形、地層、地質構造及地下水文條件之水文地質概念模型建立、(3) 區域三維水文地質數值模式之分析、(4) 模式率定與驗證、與(5) 隧道開挖湧水對鄰近區域水文地質環境影響之分析等項目詳加探討。並期藉此降低隧道於施工時所可能遭遇之風險,以釐清隧道施工與營運對於周遭環境水文地質之可能影響。
英文摘要
Taiwan is located at an active mountain belt created by the oblique collision between the northern Luzon arc and the Asian continental margin in which fissures, joints, beddings, and even faults prevail in most of mountainous areas. While existing joints and fractures provide ideal conduits for water to flow, large volumes of groundwater are stored in aquifers in which water inflows are often encountered during tunneling. Recently, several case studies of tunneling in Taiwan demonstrate that the water inflow is the major cause for the failure. As a consequence of groundwater loss, the problem of environmental arguments may also arise. In this paper, a case study of Tsengwen reservoir transbasin diversion tunnel with emphasis on the topics of hydrogeology was presented. Several major issues, including (1) the hydrogeological field testing technique, (2) the establishment of conceptual model, (3) the modeling of three-dimensional groundwater flow, (4) the calibration and verification of the conceptual model, (5) the prediction of tunnel inflow, were introduced. The application of each approach was described in details. It is believed that the predicted results may provide useful information for reducing the uncertainties of tunnel inflow and may also clarify the impact of environment issues.