Experimental Study The Salt Expansion And Frost Heave Characteristics On The Natural Saline Under Different Pressure

On the basis of consulting and organizing copious literatures, we select the natural saline soils from hami-Lop nur along the provincial highway S235, Aydingkol Lake as the experimental soil, study on the Salt-explore the frost heave properties under the condition of different pressure. aims to study pressure for different soil type, moisture content, dry density of natural saline as the inhibition effect of frost heave and thawing settlement of change rule, on this basis, the fitting of the salt-frost heave empirical formula, for salt-frost heave phenomenon of governance to provide valuable guidance. Through experimental analysis the main conclusions are as follows:(1)The analysis of Lop nur sample soil shows that pressure can restrain the salt-frost heave of sample soil, and reduce its transformation biggest cycle, but exacerbate the thawing settlement deformation.The thawing settlement coefficient increase rapidly after 1, 2 cycles of freeze-thaw cycle, and then decrease gradually. At the same time, under the condition of different pressure, lake aydingkol areas of natural saline soil in 1, 2, 3, cycle and quantity increased obviously, different regions and lop nur were systematically stud Ed.(2)Different moisture content of 1 #, 2 # soil salt-frost heave's maximum rate reduced 85.5% and94.84% respectively in 50 kPa pressure and dry density is 1.56 g/cm3, the total amount of expansion does not affect the normal operation of the road. Different dry density of soil samples also will not affect the roadbed engineering level under the condition of same pressure and the moisture content of 13.2%; When the pressure is 66 kpa, or soil samples for replacement, 2.0?0.5m can't completely prevent salt-frost heave.(3)The pressure can restrain the salt-frost heave of salty soil from Aydingkol Lake. When the pressure is little, the salt-frost heave amount is larger; Whereas smaller. When the pressure is 0kPa or8.33 kPa salt-frost heaving of the soil with superposition effect, local frost heave rate is over 4%,salt-adding salt-frost heave rate more than 8%; When the pressure is 33 k Pa to 66 kPa, salt-frost heave additive only performance in a previous cycle, when pressure is 66 kPa the salt expansion phenomenon still can be found. Pressure and salt-frost heave rate inversely proportional relationship, salt-rate of frost heave and fitting relation between the stress accords with the changes in the law of quadratic parabola.(4)The moisture content, salt content in soil samples of salt-the influence of frost heave and thawing settlement deformation is more obvious under the condition of different pressure, and the larger salt would help salt expansion. Therefore, in order to prevent the occurrence of salt-frost heaving damage,we can consider to load or adding NaCl to the soil sample for salt expansion inhibition effect, also can choose less salt saline soil in filling, try to avoid using strong saline soil filling roadbed.