Re- evaluation of behavior of deep excavations in sand

• Main Authors: Jhin-Wei Yang, 楊智崴
• Other Authors: B.C. Benson Hsiung
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/75796838872717150190

碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 101 === Deep excavation is now widely used for increasing of urban underground space, so it is important to have a full understanding in observed behavior of deep excavation. A reliable monitoring data can be used as the base of the essential basis for feedback analysis in the future. However, very few completed case histories of deep excavations in sand are seen. Therefore, it’s necessary to establish and select a deep excavation site in sand with limited interruptions to be base of later study. First, it was found that certain displacement of tip of inclinometer was occurred. Up to 66 mm of lateral displacement was seen and occurred at the depth of 19.5 m. The ratio between the maximum lateral displacement and the depth of excavation was 0.40 %. It was reported that deeper casing of inclinometer, especially deeper than wall toe can possibly reduce tip movement. The research output show that up to 22 mm of surface settlement is seen and it occurred at 2.6 m behind the wall. Approximately 50 to 60% of surface settlement was induced by wall installation. Further, corner effect may not be detected for the place more than 30 m away from the corner. Finally, the tilting of adjacent building were within 1 / 1000. Piezometric levels were continued to be lowered due to pumping in the excavation but gradually rise up after completion of excavation.