In order to control Quaternary loose layer settlement in East China, there are monitoring results based on the 3 water level observation holes and 7 sand layer of Fiber Bragg Grating (FBG) strain sensor. Under the conditions of upper group water injecting to lower group of loose layer, the deformation characteristics of upper, middle and lower group of loose sandy soil layer changing with time and relationship with the water level are studied. The constitutive relation of stress-strain is also studied at different sand layers. Research results show that using water injecting from upper group into lower group of loose layer can ease the loose layer compression deformation. With the water level dropped, in East China soil creep deformation occurred, which accord with viscoelasto plastic model. The deformation of lower sand group has clear later effect and no direct relationship with water level. The results provide an important basis for the study East China stratum settlement model and water management.
Ground-surface subsidence is a common geological disaster, which has the features of continuous, changing slowly, concealment (YP. Yin et al. 2005). Today, due to underground mining and constructions in formation compression, surface subsidence is widespread in the world, which is the environmental geological problems in the worldwide that cannot be ignored (YQ. Xu et al. 2006, D.L Galloway et al. 2000, Qiu, B. et al. 2011). The eastern region of China has generally geological disasters in coal mine geological caused by the thick loose layer settlement like as mine shaft failure. Stratum dehydration consolidation is a major cause of loose layer settlement (H.Y Liu et al. 2007).
A method of water injection using ground water to stable water level is proposed, which can effectively control the loose layer caused by compression settlement (J. Chai et al. 2012 & 2013). Accurately knowledge the characteristics of strata deformation is the premise of settlement management (Q.C. He et al. 2006). Previous research (J.F. Miu et al. 1996, X.Y Gu et al. 1998, Y Zhang et al. 2006), mainly studies are focused condition of the city pumping irrigation, deformation characteristics of middle and up loose layers.