報告書番号

U89019

タイトル（和文）

三次元浸透流の簡便解析法とトンネル掘削時の地盤沈下解析への適用

タイトル（英文）

CONVENIENT PROCEDURE TO ANALYZE THREE-DIMENSIONAL SEEPAGE AND ITS APPLICATION TO THE ESTIMATION OF SUBSIDENCE OF THE GROUND CAUSED BY TUNNELLING

概要 （図表や脚注は「報告書全文」に掲載しております）

これまでの手法では計算に要する時間が多大となり，適用がためらわれてきた三次元浸透流解析を，比較的簡便に行うことができる解析法の基本的な考え方を新たに示した。本手法では，地下水の三次元流れを簡便に解析するために，地盤を，流れに関して仮想的に多層構造を成すものと見なす。すなわち，三次元流れを，各々の層内での平面二次元流れと，層間の涵養（鉛直流れ）により表すことにする。こうすることにより，有限要素法を適用して得られる，数値計算上解くべき最終的な一次元連立方程式のマトリックスのバンド幅を，忠実な三次元解析のそれに比べて小さくすることができる。

概要 （英文）

ALTHOUGH IT IS AN ESSENTIAL TASK TO ANALYZE THREE-DIMENTIONAL BEHAVIOR OF THE GROUNDWATER FOR APPROPRIATE ESTIMATION OF THE SUBSIDENCE CAUSED BY THE SUBSURFACE WATER FLOWING INTO A TUNNEL,CURRENT NUMERICAL PROCEDURES OF THREE-DIMENTIONAL ANALYSIS MIGHT BE INCONVENIENT IN TAKING MUCH CALCULATION TIME. THE PURPOSE OF THIS PAPER IS TO PROPOSE A CONVENIENT PROCEDURE FOR THREE-DIMENTIONAL SEEPAGE ANALYSIS IN ORDER TO OVERCOME THE ABOVE DISADVANTAGE. THE PROCEDURE IS LEADON THE ASSUMPTIONS AS FOLLOWS: (1)THE GROUND IS DIVIDED INTO A MULTITUDE OF LAYERS CONCERNING THE SUBSURFACE WATER FLOW. (2)THREE-DIMENTIONALSEEPAGE IS EXPRESSED AS THE COMPOSITION OF TWO DIMENSIONAL FLOW IN EACH LAYER AND VERTICAL EXCHAGE BETWEEN ADJACENT LAYERS. THE POPOSED PROCEDURE HAS AN ADVANTAGE IN REDUCING THE BAND WIDTH OF A MATRIX FOR THE SIMULTANEOUS EQUATIONS TO BE SOLVED. FOLLOWING THE CONFIRMATION OF THE ADEQUACY THE PROCEDURE IS APPLIED TO THE EXAMINATION OF THE SUBSIDENCE OFTHE GROUND CAUSED BY TUNNELLING AND THE EFFICIENCY OF THIS CONVENIENT PROCEDURE IS DEMONSTRATED IN THE ESTIMATION OF THE RESULT OF THE TUNNELLING SPEED OR THE LINING FOR REDUCING THE SUBSIDENCE.

報告者

キーワード