強震區蘭陽平原土壤不液化原因探討

A Study on the Reasons for No Soil Liquefaction Occurring in the Lanyang Plain in a Strong Earthquake Area

徐均飛(Chun-Fei Hsu)；李咸亨(Hsien-Heng Lee)

滲透係數 ； 現地抽水試驗 ； 蘭陽平原 ； 液化分析 ； permeability coefficient ； in situ pumping test ； Lanyang Plain ； liquefaction analysis

中華防災學刊

16卷2期（2024 / 09 / 01）

125 - 138

繁體中文;英文

蘭陽平原經常發生五級以上地震，經濟部地質調查及礦業管理中心公布的宜蘭縣土壤液化潛勢圖也顯示蘭陽平原沖積扇的扇尾東側大多為高液化潛勢，為何近年來都沒有液化案例發生呢？本文試由現地抽水滲透係數、蘭陽平原的地震歷史以及土壤液化分析方法，嘗試解析宜蘭地區沒有液化之成因。為了瞭解蘭陽平原整體地層構造的透水性質和湧泉機制，本文研究能夠代表北台灣現地抽水試驗之滲透係數公式，以便全面估算蘭陽平原的整體透水性狀況。本研究發現，近年來蘭陽平原的地震規模並不大，再加上蘭陽平原的滲透性條件極為理想，因此在過去的28年裡沒有發生過災難性的液化事件。

Magnitude five or above earthquakes often occur in the Lanyang Plain. The soil liquefaction potential map of Yilan County published by the Central Geological Survey also shows that most of the east side of the alluvial fan tail of the Lanyang Plain has high liquefaction potential. Why have there been no liquefaction cases in recent years? This article attempts to analyze the reasons for the lack of liquefaction in the Yilan area based on the current pumping permeability coefficient, the earthquake history of the Lanyang Plain, and soil liquefaction analysis methods. In order to understand the permeability characteristics and spring mechanism of the overall stratigraphic structure of the Lanyang Plain, this article studies the permeability coefficient formula that can represent the in-situ water pumping test in northern Taiwan, so as to comprehensively evaluate the overall permeability status of the Lanyang Plain clearly.This study found that the earthquakes in the Lanyang Plain in recent years have not been large in scale, and the permeability conditions in the Lanyang Plain are extremely ideal, so no catastrophic liquefaction events have occurred in the past 28 years.