Study On Mechanical Properties Of Red Clay Based On Water

In this paper,based on the bottom surface of the foundation layer,the bottom surface of the foundation formed a water storage space,the formation of water channel,provides the interface for softening softening of foundation bottom surface of red clay,but also the formation of a contraction interface for the shrinkage of red clay,on building(structure)from harm.In this paper,a series of simulation experiments are designed to study the phenomenon:1.The simulation results show that the degree of disintegration,mud and softening is directly related to the degree of the fissure development.When continuous after high temperature under the condition of rainfall,dense and deep fissures,water infiltration caused by the red clay foundation in certain depth of mud,softening disintegration,overall,the formation of the soft layer,decrease the bearing capacity of foundation and deformation increases.When the high temperature and rainfall alternating conditions,sparsely fractured and shallow,seeping into the depth of the foundation is relatively shallow,red clay,clay,softening disintegration along the vertical and horizontal interval to occur,the formation of a weak zone,resulting in a decrease of the bearing capacity of foundation.Cracks open and close in the plane of reciprocating oscillation,cracks are not in the same position.The opening and closing of cracks under the action of soil and water,which reflects the interaction between the softening and consolidation of clay.2.The analysis of the physical and mechanical indexes of red clay shows that the red clay has the following characteristics:With the increase of depth,the water content increases gradually,which reflects the characteristics of "dry and wet";With the increase of depth,the water content ratio increases gradually,which reflects the characteristics of "hard and soft";With the increase of depth,the void ratio increases gradually,which reflects the characteristics of "dense and sparse";With the increase of depth,the cohesive strength of C decreases gradually,which shows that the shear strength is large and small.3.Soak water absorption and evaporation dehydration,soak quickly reach saturation,evaporation to restore the natural state of moisture content,take a long time.4.When the red clay was soaked in water,the initial cohesion decreased greatly.When the water content reached saturation state,the cohesion decreased to the lowest value.5.Ted clay soaked in water after softening,softening effect with the increase of depth and weaken,to a certain critical value,the soil is not affected by water immersion.By measuring the change of water content at different depths,the softening depth of red clay can be determined.This method is simple,quick and feasible.6.The red clay of whether there is a load,after soaking in water on the red clay foundation "softening critical depth" range of bearing capacity,deformation modulus,shear strength decreased,the decrease amplitude depends on the softening in the soaking time.Although there is no load than the case of large load,but also to reduce the amplitude of the bearing capacity of 10-20%,different soaking time,different softening depth,but the damage to the building foundation is the same.The decrease of deformation modulus is greater than the decrease of bearing capacity,the damage caused by the decrease of deformation modulus is greater than the damage caused by the reduction of bearing capacity.7.The load test results and the light dynamic penetration test results,the strength reduction is basically the same,trench excavation process,the light dynamic penetration analysis of water softening strength decrease,and provide basis for design.8.According to the indoor and outdoor expansion test,it shows that the outdoor test index is bigger than the indoor test.It is dangerous to analyze the swelling of red clay according to the indoor indexes.Therefore,this paper put forward to the red clay expansion evaluation,regardless of the size of the free expansion rate of expansion,as long as the total rate of greater than 1%or the free expansion of the expansive soil to determine the critical value,should be set for the expansive soil,and the expansion of evaluation;swelling force tests shall be carried out in the expansive force test.Fixed indoor test methods at present red clay swelling pressure.9.Through the simulation test,the red clay in the soil under the existing water disintegration,mud,softening effect type,strength index in certain depth,are reduced in different degree,the construction may lead to adverse harm.Through the analysis of the case,it is confirmed that the soil and water effect of red clay is softened,and the reduction of bearing capacity is basically consistent with the experimental results.The corresponding measures should be taken to prevent and control the use of soil and water in the construction of red clay.The author puts forward some prevention measures.