報告書番号

U86050

タイトル（和文）

連続地中壁の本体構造物への適用に関する検討－重ね継手を有するリング型ＲＣ部材の破壊性状－

タイトル（英文）

MECHANICAL BEHAVIOUR OF RING TYPE REINFORCEDCONCRETE MEMBERS WITH LAP SPLICES

概要 （図表や脚注は「報告書全文」に掲載しております）

大深度地中構造物の構築工法として，連続地中壁（連壁）工法がある。従来，連壁は土留め・止水のための架設構造物であった。しかし，施工技術の向上と施工実績の増加により，設計・施工法の合理化の観点から，連壁を本体構造へ適用するという考え方が生まれ検討が行われている。本研究は，連壁そのものを本体構造に適用するという観点から，地中線立坑を対象とした重ね継手を有するリング型鉄筋コンクリート（ＲＣ）部材を作製し，地震荷重を想定した破壊実験を実施することにより，構造体としての耐荷機能の健全性について検討したものである。実験結果から，重ね継手を有するリング型ＲＣ部材は主鉄筋状までは鉄筋連続の場合とほぼ同じ変形挙動を示した。また，鉄筋降状後重ね継手部に付着割裂ひびわれが発生するが，変形能は鉄筋連続の場合と同等でかつ降状時と同等の耐力を保持していることが明らかとなった。

概要 （英文）

THE CONTINUOUS UNDERGROUND WALL METHOD IS APPLIED TO THE CONSTRUCTION OF THE RC UNDERGROUND STRUCTURES SUCH AS LNG TANKS AND THE DEEP PITS FOR THE UNDERGROUND TRONSMISSION LINES. CONTINUOUS RC WALL IS A TEMPORARY STRUCTURE AND IS CONSFRUCTED TO DISTURB THE WATER STREAM IN THE GROUND AS WELL AS THE COLLAPSE OF THE EARTH WALL. FROM A VIEWPOINT OF THE RATIONALIZATION OF THE DESIGN AND CONSTRUCTION METHOD,A NEW CONCEPT,THAT IS THE APPLICATION OF THE CONTINUOUS RC WALL TO A PART OF OR THE WHOLE OF RC UNDERGROUND STRUCTURE WAS INVESTIGATED BASDED ON THE TECHNICAL IMPROVEMENT AS WELL AS THE INCREASE OF THE RESULTS OF THE CONTINUOUS UNDERGROUND WALLS. IN THIS STUDY,RC RING MEMBERS,ON WICH THE PITS FOR THE UNDERGROUND TRANSMISSION LINES WERE MODELED,WERE LOADED UP TO FAILURE AND THE RESULTS OF THE EXPERIMENTS WERE INVESTIGATED. CONCLUVSIONS CLERIVED FROM THE EXPERIMENTS WERE AS FOLLOWS. (1)THE INFLUENCE OF THE DIFFERENCE BETWEEN WITH AND WITHOUT LOP SPLICES OF RC RING MEMBERS ON THE RELATIONSHIP BETWEEN LOAD AND DEFLECTION WERE NOTOBSERVED IN THE ELASTIC REGION OF REINFORCEMENTS. (2)SPLITTING CRACKS ALONG REINFORCEMENTS DUE TO BOND FAILURE OCCURRED AT THE PORTION WHERE LAP SPLICES WERE EMBEDED AFTER YIELDING. HOWEVER,THE DEFOR MOTIONAL CAPACITY OF RC RING MENBER WITH LAP SPLICES WAS ALMOST THE SAME AS THAT WITHOUT LAP SPLICES AND THE STRENGTH AT FALURE WAS CLOSE TO THE YIELD STRENGTH. (3)IN WAS CONFIRMED THAT THE CONTINUOUS RC WALL COULD BE APPLIEDTO THE STRUCTURAL MEMBERS.

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