Abstract: The soft soil foundation of the section K132+177～+258 of Langfang-Cangzhou Expressway in Hebei province is mainly composed of low liquid limit, middle-high compressibility clay layer, belonging to the type of coastal sedimentary deposit, which is treated mainly adopting static grouting. The test and laboratory studies respectively for grouting construction method of whole pore disposable and top-down segmentation tabulator in field are taken. On the basis of physical and mechanical properties of soft soil foundation and observation data of grouting test surface deformation amount, the diffusion processes of slurry in different grouting construction methods (whole pore disposable and top-down segmentation tabulator grouting) and different grouting pressures (0.5, 1.0 MPa and 2.0 MPa) are studied by using FLAC3D. The results show that the grouting effect of top-down segmentation tabulator grouting is better than whole pore disposable grouting in the same grouting pressure; and the increasing pressure is beneficial to grouting diffusion. But it would result flow-up of grout with the higher pressure. Therefore, we should choose reasonable grouting pressure according to the practical site situation

Key words: Langfang-Cangzhou Expressway, soft soil foundation, grouting construction, process of grouting diffusion, numerical simulation