Numerical Analysis And Applied Research On The Artificial Hard Shell Foundation Under Low Loads

Widespread soft foundation in the coastal areas, through the curing process，can formedartificial hard shell layer with high strength on the surface of soft soil quickly. The hard shelllayer has a sealing function to the soft soil under the foundation,and can inhibit the deformationof soft foundation. Numerical analysis the additional stress and deformation of soft foundationoverlying hard shell,it has great engineering significance and economic benefits in practicalengineering applications.In this paper, simulation analysis of the additional stress and deformation of soft foundationoverlying artificial hard shell layer by finite element software plaxis3D, and through theoreticalderivation, giving a solving method to the bearing capacity problem of soft foundation overlyingartificial hard shell layer, the main research contents are as follows:(1) Analysis of the additional stress factor of the soft foundation overlying artificial hardshell layer. Given the variation of additional stress factor of soft foundation overlying artificialhard shell layer under the rectangular and strip load. The results show that vertical additionalstress factor of soft foundation overlying artificial hard shell layer decreases gradually asthickness and modulus ratio of artificial hard shell layer increases, the decrease amplitude of softfoundation overlying artificial hard shell layer relative to the soft foundation is linear with thethickness of artificial hard shell layer. Influence depth of rectangular load to the additional stresscoefficient is shallower, when the soil reaches a certain depth, the vertical additional stresscoefficient tend to equal under rectangular and strip loads;(2) In the finite element analysis, using two different types of units to numerical simulation.The results show that,when regarded artificial hard shell layer as board body to calculation, thevariation of vertical additional stress factor is more reasonable;(3) As the artificial hard shell layer has a closed role to the soil, the level of the additionalstress generated in the soft soil have been improved significantly, lateral stress coefficient of soilK0increased significantly within a certain range away from the loading plate width, and as thedepth of soft soil increases, K0decreases gradually;(4) By numerical calculation, comparative analysis of deformation between soft soil andsoft foundation overlying hard shell;(5) Using the static equilibrium theory and limit equilibrium conditions, deduced thebearing capacity of foundation formula that considering the role of shear of hard shell layer, andgives the chart bearing capacity coefficient, verified the formula by calculating the examples,and analyzed ultimate bearing capacity of three different foundation type, given the size of theirrelationship;(6) Comparing the results between load test of indoor and bearing capacity theoretical formula,and engineering practice has proved this point.Finally, summarize the work that has been done, and discuss the further research.