Mechanism Study Of The Soil Shearing Strength Under The Changing Of Environmental Factors In Geermu Region

Soil samples in this paper come from suburb of GeErMu, starting with fundamental engineering properties, the salt heaving characteristics of saline soil is analyzed by measuring ion component of freely soluble salt and salt heaving experiment; From different water content, salt content and salt style, the changes of shearing strength properties under partial environmental factors and different soil combination is studied, and mechanism explanation of thesefactors' effects is made; On basis of scanning electron microscope (SEM)pictures, the change mechanism of soil's mechanics parameter under alternation of freezing and thawing in view of microstructure is made; Sensitivity analysis of shearing strength parameter is made from water content, salt content and both interaction.According to bulk of experiment studies and theoretical analysis, the result shows that the soil samples in experiment is silty clay; Cl^-/SO₄^2- is 3.162 from soluble salt analysis, the soil can be named salt-bearing-soil by norm, so samples in this experiment is chloride clay; In the same of water content, sodium chloride restrains salt heaving, but contrary to sodium sulfate; The content of sodium sulfate is between 2 percent to 6 percent, salt heaving is obvious, however, the salt heaving rate slowly increases when salt content is more than 6 percent; When water content is less than 16 percent, Salt heaving rate increases and it gets maximum when water content is 16 percent or so, which is optimum water content of soil, that is to say is 15.56 percent; When water content overruns 16 percent, the salt heaving rate is contrary; Salt heaving increases when temperature decreases until to extreme, sodium sulfate- bearing-soil starts salt heaving when temperature is 15 centigrade, salt heaving is maximum in condition of below zero 6 centigrade.Cohesion and inner friction angle decreases with increasing of water content, but the increasing current of inner friction angle is correspondingly slow, If water content is fixed, strength parameter minishes initially and increases subsequently. Strength parameter gets minimum when salt content ofadding Cacl2 is 10.36 percent, but the minimum appears at 8.36 percent whileadding Na2SO4. If water content is lower, this current is not evident. Afteralternation of freezing and thawing, cohesion and angle of internal friction decreases with increasing of periods of freezing and thawing, and decreasing stage is first and second cycle, the trend of curve turns smooth with increasing of periods of freezing and thawing; The relationship of strength andmicrostructure is set up by Scanning Electron Microscope (SEM) pictures; By ingenuity analysis, interaction significantly influences cohesion and angle of internal friction when notable level( a) is 0.05, water content and salt contenthas prominent effect on mechanics parameters when notable level( a) is 0.01.