학술논문

Evaluation of In-situ Loading Test and at Deep Pleistocene Clay Layer for Settlement Prediction of Highway Bridge / 道路橋基礎の沈下予測のために実施した大深度更新統粘土層における原位置載荷試験とその評価
Document Type
Journal Article
Source
地盤工学ジャーナル / Japanese Geotechnical Journal. 2018, 13(4):431
Subject
Pleistocene clay
coefficient of secondary compression
consolidation yield stress
in-situ loading test
overconsolidation
二次圧密係数
原位置載荷試験
圧密降伏圧力
更新統粘土
過圧密
Language
Japanese
ISSN
1880-6341
Abstract
For the design of pipe foundation of large-span bridge, in-situ loading test on the deep Pleistocene clay layer was carried out. The loading plate, the diameter of which was 250mm, was placed on the Pleistocene clay layer at 70 m depth utilizing the bore hole. The settlement was observed for 9 months, in which the step loading was given by the hydraulic jack. Measured settlement showed the periodic fluctuations related with the tidal change, and the settlement continued with time and the tendency of convergence was not shown within the 9 months. The compression strain of Pleistocene clay calculated from the measured settlement was almost same as that predicted from the consolidation yield stress and coefficient of secondary compression obtained from laboratory test of undisturbed samples. The settlement-time relationship of in-situ loading test was explained by the numerical analysis in which Cam-Clay model was used for the Pleistocene clay layer.