編號： 029
題 名：澎湖群島玄武岩殘積紅土的工程地質研究 (I)
The Engineering Geology Study of the Basaltic Residual Laterite at Penghu Area. (I)
研究者：陳宏宇 Chen, Hongey
機構名稱：台灣大學地質研究所 (NTUGGEOG)
研究日期： 1993/08 - 1994/07
出版日期： 1994/09
頁冊數： 69
中文摘要：本研究工作主要係嘗試利用一些室內試驗方法及野外調查工作來瞭解澎湖地區之玄武岩殘積紅土的工程地質特性。從第一階段之研究結果顯示此殘積紅土具 有下列特性 ,在自然物理性質方面,其顆粒組成主要是以黏土為主,少部分為粉砂質黏土及砂質黏土。液性限度介於20.65%至66.87%,塑性限度 介於35.89%至41.12%,塑性指數介於11.57%至24.41%,活 性比介於0.251至0.398。在礦物組成方面,以高嶺石、膨潤石、伊萊石、石英為主。綜合本研究結果發現澎湖地區殘積紅土因受母岩岩性之不同所控制,大致可以分成兩大 類型,並具有下列特性:類型(I)由玄武岩或火山碎屑物質經風化淋溶而成。此類紅土顆粒度較細,黏土顆粒含量 較高,紅土化程度較高,含鐵鋁氧化物較高,比重 較大,屬高塑性粉砂(MH),黏土礦物為高嶺石、膨 潤石,自由膨脹度較高。類型(II)由砂質沈積岩經風化淋溶而成。 此類紅土顆粒度較粗,黏土顆粒含量較低,紅土 化程度較低,含鐵鋁氧化物較少,比重較小,黏土 礦物為高嶺石、伊萊石,自由膨脹度較高。
英文摘要： The purpose of this research work is to understand the engineering geological characteristics of basaltic residual laterite by experimental test and field investigation on the Penghu area. The results of the first step experimental test demonstrate that the main particle compositions of residual laterite are clay fractions, and the other distributions include silty clay and sandy clay. In general, the liquid limits range from 20.65% to 66.87%, and plastic limits range from 35.89% to 41.12%. The plastic index is around 11.57% to 24.41%, and activity is around 0.251 to 0.398. The main constitutions of clay minerals are kaolinite, smectite, illite and quartz. The results of field investigation show that the residual laterite has two different types and has following characteristics: Type (A): The residual laterite was leaching by basalt and volcanic material. The particle size of this laterite is more fine and has higher content on clay fraction. The laterization degree of this geomaterial is also higher and has high specific gravity. The geomaterial was classified the high plastic silt. The clay mineral compositions include kaolinite and smectite, and have higher free swelling grade. Type (B): The residual laterite was leaching by weathering sedimentary rock. The particle size of this laterite is more coarser and has low content on clay fractions. The laterization degree of this geomaterial is low and has low specific gravity. The clay mineral compositions include kaolinite, illite and have higher free swelling grade.
