Study On The Special Properties Of Strength Of Solidified Saline Soil In Inshore

The soil contained a lot of salts is named saline soil, and it is a special soil. In usually saline should be treated before using for road embankment of highway. According to geographic distribution, types of saline soils are divided into inland and inshore saline soil, they are sulphuric, carbonic, chloric saline soil in accordance with origin and salt type. Because of marine deposit, chloric salt in saline soil is much.In the west land of Bohai gulf there are a lot of saline soil which has expansion, depression and corrosion except of serious water absorbing quality, it make solidified soil soften partially. Area alone coastal line has rich and good economic basis, large scale road construction and beach development contain research work on changing its inherent properties and solidifying of saline soil, especially Hebei province and Tianjin municipality located in west land of Bohai gulf. Therefore the research results have developed not only new theories, but also it has a guide role for engineering construction.In the condition of great temperature difference, upper underwater table, much clay, more height of capillary rise, higher precipitation intensity, etc., saline soil show features as follows: salt accumulation in the top in spring, salt crystallizing with the density of salt resolution, serious capillary action. As a use for road embankment, main purpose of solidified saline soil is to increase its strength, stability in water, durability in natural. Meanwhile solidified materials should be economical, no pollution, and convenient to use. Solidified saline soils with lime and polymer-SH agent have been tested in laboratory and in-situ, and used in highway from Cangzhou to Huanghua harbor, the research results suit for the demands of specification. Main research contents and results are as follows:1. Summarized on origin and distribution of saline soil, difference of salt content value in vertical and horizontal direction, main problems of engineering geology, and popular treating means.2. Experimental research on effect of salt content on physical and hydrological properties of saline soil in inshore be carried out, and found the limit value of salt content which has significant effect on physical properties, grain size distribution, consistency indices etc., which has a guide role for research of solidified saline soils.3. All kinds of solidified methods, such as lime, cement, ash, and polymer-SH agent, are tested on the condition of different ratio of materials so as to obtain unconfined compression strength etc. A lot of factors effected on unconfined compression strength, including curing period, mixing water, soaking water, degree of compaction, and salt content, as well as desk study on stability in water, frost resistance, and durability, all be tested and analyzed. It has been certified that solidified soil with 1% SH agent and 6% lime has a very high strength and excellent stability in water, and meet the requirements of road embankment.4. Inspection of microstructure by means of microscopy, polarizing microscopy and SEM, and test of XRD and infrared spectrum analysis on the samples of solidified montmorillonite, kaolinite, quartz, and saline soil with SH agent be carried out for research of mechanism of solidifying action. It have been certified that SH agent encloses soil particles and make the connection like fishing net between particles and in void, which increases the strength of solidified soil. After curing period of three weeks web connection remains stability, which demonstrates reaction between SH agent and soil particles is not reversible and not soften in water.5. The physical properties, unconfined compression strength, shear strength, microstructure indices of samples of solidified soil with lime have been carried out on the condition of different salt content. It have proved that microstructure indices of solidified soil correlate with strength and a different of salt content effects on physical properties, strength, microstructure indices and it's fractal dimension in certain degree.6. In order to testify suitability of desk research, in-situ compaction test of solidified soil with lime and lime + SH agent be carried out in coastal highway located in Fengnan county of Hebei province, deflection value, rebound modulus, California Bearing Ratio, Degree of compaction, etc. is inspected in site. Meanwhile unconfined compression strength, shear strength, California Bearing Ratio, and compression is tested with same saline soil and same solidifying materials. The results of in-situ survey and laboratory research meet the requirements of road embankment of highway. 7. Solidifying materials ratio, mixing and compaction technology suitable to all kinds of profile of road embankment is submitted for highway construction in inshore.8. First summary on research results in laboratory and in site, then completed the embankment construction of solidified saline soil with lime and lime +SH agent in highway from Cangzhou to Huanghua harbor, last deflection value, rebound modulus, California Bearing Ratio, Degree of compaction, roughness, etc. is inspected respectively in up and down roadbed. It has proved that solidified saline soil with lime and SH agent can meet requirements of embankment for highway, and has the feathers of well technology, convenient to construction, suitable price.The future research topics about solidified saline soil have been mentioned in this paper, such as variable regulation of microstructure indices, strength of particle and cement agent of solidified soil in microscale.