The Experimental Study On Coefficient Of Collapsibility And Salt-frost Heaving Character Of Strong Chlorine Saline Soil In Lop Nor

Lop Nur region is extremely rich in mineral resources and reserves, with the continuous development of mineral resources in Lop Nor and various buildings are increasing gradually,the saline soil problems are becoming a serious problem. In order to ensure the building design, construction and road safety of Lop Nor area, it is very important to study the engineering character of Lop Nor saline soil.In this paper, the main object of study is the saline soil of Lop Nor,by laboratory experiments their basic physical and mechanical properties were tested. Collapsibility of saline soil were tested under side limit conditions, The results showed that, the coefficient of collapsibility of strong chlorine saline soil decreases gradually with the increase of the initial dry density and initial water content;under the same pressure, the coefficient of collapsibility decreases gradually with the increase of the dry density and water content; When the dry density and water content unchanging, the coefficient of collapsibility increased with the increase of the pressure. When the pressure within200kPa, the coefficient of collapsibility have the largest increment, the coefficient of collapsibility have the most sensitive.when the soil have the same water content, the soil of smaller dry density, which have larger ratio of total collapsible under200kPa, with the pressure increasing, the collapsibility coefficient increment decreases gradually;when the soil have large dry density, the coefficient of collapsibility have the largest increment, but it still increase with the increase of pressure, This phenomenon is the most obvious when the water content is13%. When the water content of10%in soil, the coefficient of collapsibility have the largest increment under various pressure.The process of deformation in Freeze-Thaw cycle could be separated into three phases; the stage of salt expansion, the stage of salty-frost; the stage of thawing settlement. The increment of salt expansion ratio of strong chlorine saline soil was increased gradually with increasing cycles. When the dry density unchanging, the water content is optimum moisture content,the soil have the largest salt expansion ratio;when the water content unchanging,the salt expansion ratio changed very little with dry density increasing.