| The artificial freezing method is being applied increasingly in the field of urban construction, producing frozen wall with high strength and low penetrability. But people find it difficult to mitigate the effect on surface and sub-surface structures which arise as a consequence of frost heaving and thawing settlement.Grouting has become a viable geotechnical method to improve the bearing capacity and prevent the ground drainage. In this paper, a combined application of grouting and ground freezing method is proposed, using grouting technique to strengthen soil before freezing. The major works are as followed:(1)A numerical model has been described to simulate the grouting process in soil. Several numerical simulations was carried out to illustrate the effect of soil elastic modulus and depth on the development of grouting veins. A series of simulations were conducted to study the compressive deformation of grout-improved soil. The relationship between grout-improved soil elastic modulus and grouting ratio was established.(2)Numerical analysis was performed to study the frost heaving and thawing settlement of grout-improved soil. Comparison on displacement field was made between grout-improved soil and pure soil, which helps to explain the reason why grouting can reduce frost heaving and thawing settlement. Based on the numerical results, the relationship curves between grout-improved soil frost heave ratio and grouting ratio was obtained. Furthermore, the relationship between thaw settlement ratio and grouting ratio was achieved.(3)Based on the relationship curves mentioned above, a finite element analysis was made to simulate the actual case of soil reinforcement by grouting-freezing method. Both surface movement and segment deformation induced by frost heave and thaw settlement were analyzed. The influential characteristics of various factors including grouting ratio, grouting length, grouting radius and grouting method are obtained. |
PDF Full Text Request