Swelling and shear properties of friction-reducing polymer and prevention of ground deformation due to pull-out of temporary sheet piles

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420499
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geotechnical engineering
• Research Institution: Shinshu University
• Principal Investigator: UMEZAKI Takeo 信州大学, 学術研究院工学系, 教授 (50193933)
• Co-Investigator(Kenkyū-buntansha): HINO Takenori 佐賀大学, 低平地沿岸海域研究センター, 教授 (20295033) ; KAWAMURA Takashi 信州大学, 学術研究院工学系, 准教授 (50324231)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 地盤工学 / 土留め工 / 鋼矢板 / 周面摩擦 / 地盤変状 / 吸水性高分子 / 拘束圧 / 土中水のイオン成分

Outline of Final Research Achievements

(1) The ion concentration was investigated for the cement improved ground. Furthermore, simple swelling tests were carried out and the water-absorbing ratio, Ramax, of the friction-reducing polymer (FC agent) in aqueous solution of various metal ion was evaluated. (2) Swelling and permeability test for pure water, artificial sea water, and cement water under confining pressure, p', were conducted. The relations of Ramax, p' and the coefficient of permeability, k, were evaluated. The value of k is very small; the FC agent is impermeable material. (3) The friction angle of FC agent obtained from box shear test is δ=1°(c’=0) which is strength parameter related to effective stress. Moreover, the friction angle on the contact surface between soil materials and FC agent is also δ'=1-3°(c’=0). (4) The settlement of ground surface due to pulling out of sheet piles coated with FC agent is small, and the influence range can be evaluated about 45°from lower end of the steel sheet pile.

Free Research Field

地盤・環境地盤工学