Research On The Characteristics Of Three Axis Creep Of Marine Soft Soil Experiment In The Occurrence Environment

The new lands and natural sedimentary sitesformed after sea reclamation have extremely different genetic properties and engineering characteristics.In order to investigate the characteristics of Creep propertyoflower lying marine soft soil under the changes ofthe occurrence environment caused by sea reclamation.,this thesis takes marine soft soil collected from Qisha industrial park of Fangchenggang of Guangxi as the research object,Through the mechanism of simulation technology imitated changes of environment factorsofmarinesoft soil in land reclamation process,adopts three loads and three solutions to make the artificial sample "imprinted" withoccurrence environment elements;The samples were prepared by routine laboratory structural mechanics test and three axis consolidation non drainage creep test to analyze the influence of environmental changesonmacroscopic mechanical properties of marine soft soil;Pressure mercury injection test on soil samples from immersion test and onbroken soil samples from triaxial creep tests.Throughthe changes of pore characteristics after creep,comprehensively analyze the influence of the changes of occurrence environment on creep property ofmarine soft soil.Through comprehensively analyzes creep property of structural marine soft soil under the influence of the change of occurrenceenvironment,this thesis gets the following conclusions:1. Through the "soak-loading marine soft soil apparatus"and during a three-month period of sample preparation, the axial settlement of the "soak" mould was observed.finds that the environment elements have effects on the property of subsidence deformationsettlement of marine soft soil.2. Doing penetration test,shear and compression tests on marine soft soilimprinted environment elements,analyze the effect of the occurrence environment on void ratio,permeability coefficient,pre consolidation pressure, consolidation characteristics, consolidation coefficient, shear strength index and so on. The results of this thesis are as follows:(1) Void ratio and permeability coefficient of marine soft soil would be influenced by changes of environmental factors,the increase of the two factors will make the marine soft soil become dense, and the effect of overlaying load is more significant. (2)The enhancement of Ca2+concentration to a certain extent changes the internal structure of the soil,and the yield strength of soil samples can be improved.The higher the concentration, the greater the yield strength of the soil samples. (3) The variety rule of mechanical parameters are obtained from the results of fast shear and three axis shear tests:The shear strength of marine soft soil can be improved by the two kinds of environmental factors, which are the overlaying load grade and the Ca2+concentration.In the above, the cohesive force is mainly determined by the overlaying load, and the Ca2+ion concentration mainly affects the internal friction angle of the marine soft soil.3. Data of creep tests were disposed by Chen’s method,and the results of three axis consolidation and non drainage creep test are analyzed qualitatively, which gets the results as follow:The long-term shear strength of the marine soft soil can be enhanced by the overlaying load level and the Ca2+ concentration,among them, the overlying load mainly affects the cementing strength of the marine soft soil to resist low grade deviator stress, and the Ca2+ concentration has a significant effect on the failure stress of the marine soft soil.4. With the mercury intrusion method,the the micro pore characteristics of marine soft soil betweenthe soak-loading tests and the destruction of the three axis creep testsare compared,which the influence of environmental factors on the creep characteristics of marine soft soil is analyzed from the micro angle.The creep mechanism of marine soft soil is investigated by means of macro and micro integration, which acquire a further understanding of it.