斜面崩壊の地質学的研究
スポンサーリンク
概要
- 論文の詳細を見る
The authors thought that a breakdown of a slope is basically attributable to the augumentation of the slopes instability potential, and that the time-variation of causative characters related to geological and topographical conditions must be taken into account in the discussion of the mechanism of landslide development.<BR>The Chichibu basin was chosen as the area of the present study, and the mechanism of landslide development was considered mainly from the geological stand-point. The major object was the landslides caused by the action of weathering.<BR>Bedrocks<BR>The physical properties of rocks are correlated to one another, and it has become clear that they can be represented by the uniaxial compressive strength and the dry shrinkrage ratio.<BR>Among the Tertiary rocks of the Chichibu Basin, mudstone shows that its physical properties vary with geological horizons, and the ralation between its physical properties and the geological horizons is represented by two cycles which correspond to the Oganomachi group and the Chichibumachi group respectively.<BR>Weathering zone<BR>The weatherability of fresh rocks can be expressed by the uniaxial compressive strength and the dry shrinkage ratio. A weathering zone is easily developed in a area where the basement is composed of rocks with small uniaxial compressive, strength and large dry shrinkage ratio.<BR>A weathering zone can be divided into four subzones, I-IV, from the ground surface to the fresh bedrock down below. The physical properties of each subzone change according to the degree of weathering, but their changes from one sabzone to another are gradational.<BR>Moreover, it has become clear that the quantity of cracks in the weathering zones of the study area is far from negligible.<BR>Development of weathering landslides<BR>On the basis of the factors which augument the slopes instability potential with the lapse of time, the authors classified the landslides into three groups, namely, the weathering landslide, the stream erosion landslide, and the head erosion landslide. In the present paper the authors focussed the discussion on the mechanism of development of the weathering landslide.<BR>In order to infer the state of development of the weathering zone before the breakdown of the slope, the authors carried out seismic prospecting along the margin of the destroyed slope. There are two types of landslides, one occurs mostly in the first velocity layer with less than 0.4 km/s, and the other extends down to the second velocity layer with 0.4-0.8 km/s. It is evident that the character related to the cracks of the weathering zone and to the softening of rock fragments is contributing to the development of landslides.<BR>The depth of the weathering zone has its limit in accordance with the slopes gradient. The depth of the weathering zone increases with time, and in this process the part that overstepped the critical stability would be broken down.
- 社団法人 東京地学協会の論文
著者
関連論文
- 硝酸態窒素による浅層地下環境汚染に対する関東ロームの応答(環境汚染問題に対する応用地質学の貢献)
- I. 地殻変動と地震断層 : (応用地質学からの観点 : 兵庫県南部地震)
- 気泡を含む液体に浸された多孔質媒質中のP波伝播の温度依存
- 那須野が原の地質構造,特に那珂川旧河道の変遷について : 那須野が原の水理地質・2
- 地震防災技術委員会の活動状況
- 兵庫県南部地震により生じた河川護岸の低角度クラック
- 室内鉛直断層模型実験で観察された寸法効果に関する考察
- 信州麻績地域における地下水の弗素含有量と地質構造との関係(予報)
- 火山灰土を用いたカラム試験から得られる硝酸態窒素の吸着特性
- 一湧水における水質の経日変化と地域環境要因
- 花崗岩類分布域における古来のたたら製鉄と斜面崩壊
- A11. ローム土における硝酸態窒素の吸着について(第48回粘土科学討論会発表論文抄録)
- 市川慧前会長のご逝去を悼む
- 応用地質の新たな飛翔へ
- 地下水は生き残れるか
- 扇射探索法による採石場斜面の安定性評価
- 方解石の溶出に伴う泥岩の組織と物性の変化
- 斜面表層の厚さと分布形態について : 弾性波探査資料の分析
- 水分ポテンシャルからみた泥岩の乾燥収縮と湿潤膨張
- 秩父盆地内道路切取法面の風化後退と岩質について
- 弾性波速度による割れ目の定量化について
- 泥質岩の含水による強度変化
- 三浦半島の三浦層群について
- 秩父盆地北東隅部第三系の地質構造
- 白濱層群の堆積状況 : 下田町東方の地質
- 伊豆天城山南部の湯ケ島層群
- 地すべり土層の水文地質学的検討と融雪水の動態 (II) : 新潟県北魚沼郡入広瀬村横根地すべりを例として
- 地すべり土層の水文地質学的検討と融雪水の動態 (I) : 新潟県北魚沼郡入広瀬村横根地すべりを例として
- 那須野が原の"関東ローム":那須野が原の水理地質・4
- 那須野が原の地史 : 那須野が原の水理地質・3
- 斜面崩壊の地質学的研究
- 長瀞付近の地下水 : 地下谷の地下水調査の1例