When abnormal deformations appear, we should take measures to control them. It is also necessary to install monitoring equipment to observe deformation. All the evidence indicates that the boundary region is critical for filling projects. Additionally, the difference in volumetric water content and permeability coefficient may trigger different mechanical properties on both sides of the boundary. Laboratory tests show that the difference in soil compression properties is one of the reasons for these deformation characteristics. Deformation in different places is different during the winter: (1) for vertical displacement, uplift is present in the cut area, settlement is present in the fill area, and heterogeneity is evident in other areas (2) for horizontal displacement, the expansion state is present in the filling area and the compression state is present at the boundary. The results show that stress and deformation increase rapidly during construction. We obtained the horizontal and vertical displacements, internal deformation, water content, and pressure, according to the air–space–ground integrated monitoring technique. Therefore, we monitored the deformation through InSAR and field monitoring to investigate the deformation characteristics and their causes. However, undisturbed loess and remolded loess have different mechanical characteristics, which may influence the stability of the filling process. Several land-creation projects, such as the Lanzhou New Area (LNA), have been undertaken in China as part of the Belt and Road Initiative to bring more living space to the local people in loess areas. The research in this paper provides the experimental basis for related studies. Finally, based on the test data, the sensitivities of the loess collapsibility coefficient and self-weight collapsibility coefficient to loess parameters were analysed. Then, the gravity load of the water in the infiltrated loess was calculated and compared with the gravity load of the loess. This paper monitored the settlement law of loess over time through shallow and deep punctuations buried in loess, which results in daily settlement and 65 d cumulative settlement. Under the action of its own gravity loads and the gravity loads of water, the phenomenon of overall settlement and collapse appears. The collapsibility of loess means that after water infiltrates into the pores between the loess particles, it destroys the original pore structure of loess and causes the strength of loess to rapidly decrease. As a continuation of prior research, this paper will further study the collapsible settlement characteristics of loess. ) analysed and studied the law of water infiltration in loess. A further 90 days storage test shows that the final infiltration depth of water was about 7 m.Ī previous study (Meng et al. The results of rain period test show that the water infiltrated into the loess about 3 m after 25 days of rainfall. ![]() Through the rain test and water storage test of a loess-filled surface, the relationship between the moisture content and depth of the backfill loess before and after rainfall and storage is obtained. ![]() Finally, the vertical and horizontal penetrations of water in the loess are analyzed, and the range of water immersion and saturation are determined. The results of the in situ immersion test show that the vertical seepage velocity of water was very fast, and the infiltration depth was close to 25 m after 9 days of water storage, and at the interface of the new loess, the paleosol, and the old loess, the water infiltration line appeared to be refracted. This paper analyzes the results of in situ water immersion test (in order to study the permeability of water storage in undisturbed loess), rainfall test (in order to study the permeability of rainwater in the backfill loess), and water storage test (in order to study the permeability characteristics of water storage in backfill loess) on the filling site and studies the permeability law of water in unsaturated layered loess and backfill remolded loess. In Chinese loess areas, irrigation, water storage, and rainfall affect the stability of the original loess structure and cause damage to the foundation. Loess has the characteristics of complex structure and reduced mechanical strength after encountering water.
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