Research On Bi-directional Cement-soil Mixing Column For Reinforcing Marine Soft Soil Of Lianyungang

Now,with the rapid development of China's economy,cement-soil mixing piles have been widely used in highway,port,civil engineering and other fields.In many years of engineering application,it is found that there are some problems which are difficult to overcome in the conventional cement mixing piles.The results are not satisfactory,and it is often difficult to meet the design requirements.In view of this phenomenon,domestic scholars proposed using the new technology with bi-directional cement-soil mixing pile in reinforcing soft soil foundation.Bi-directional cement-soil mixing pile device which is basis of a one-way device of cement-soil mixing piles by increasing power device and drill pipe.This new equipment is seldom used in the railway construction.its effect is still at the exploratory stage.In this paper,the reinforcement effect of single and bi-directional cement-soil mixing pile is studied by combining with Lianyungang-Yancheng railway.First,we have the geological survey in test section to master the engineering characteristics of reinforced soil.Lianyungang soft clay with high compressibility,porosity,water content,clay content and high thickness of soft soil characteristics.Secondly,prior to construction we have the indoor cement-soil ratio and based on the strength of cement-soil with cement content,age,relationship types summary calculation formula of strength of cement-soil.Finally,according to the ratio test to determine the parameters and guide site construction.Based on unconfined compressive strength of pile test and load test checked single and bi-directional cement-soil mixing pile quality,and compared the test results.Final conclusions show that the bi-directional cement-soil mixing pile has been significantly improved than single cement-soil mixing pile in strength and rigidity,and the effective length of the pile is significantly increased.