Research On Blasting Compaction Treatment Technology For Deep Soft Soil Foundation On Deep Water Conditions

Currently blasting compaction processing technology is widely used inlarge-scale reclamation projects and port construction. It concerns with nationalwell-being and the people’s livelihood and is of great significance. As an increasingnumber of the projects constructing on the deep soil foundation of deep water, it isnecessary to systematically research into the design, implementation and safetyassessment of the blasting compaction processing technology on the deep soft soilfoundation of deep water.Blasting method to squeeze and replace mud has certain restrictions for depth ofthe soft soil foundation treatment. The existing technical regulations restrict the depthfrom4to12meters. Although blasting method to squeeze and replace mud break theprovisions of the depth which is less than12m, the experimental implementationresults show some problems such as silt riprap does not fall at the end of the ground,post-construction settlement is big, blasting filling core has a big section and thepractical amount of riprap is far beyond the design engineering quantity. Theseproblems bring great negative impacts on the wide application of the blasting methodto deal with the soft soil foundation in Zhejiang water reclamation projects.Combining Ligang fishing port east breakwater’s engineering practice of blastingcompaction method to deal with soft soil foundation, the text research into theselection of charge loading tool, the reasonable determination of dumping fillparameter (elevation to throw fill, width to throw fill and footage to throw fill), theblasting parameter and quality detection method in construction period. Main resultsof the study are:1）With self-developed new type charging device, it realized the standardizing ofcharging operation, reduced the construction costs and the number of operatingpersonnel, and improved the blasting efficiency and construction safety conditions toensure the blasting quality.2）Combining the borehole detection with geophysical exploration to detect the transverse and longitudinal profiles’ position of breakwater and controlling the riprapboundaries can help the actual formation of the profiles meet the design request.3）The introduction of the millisecond blasting for compaction processing softsoil foundation reduced the impact on the surrounding buildings and marine life. Theresults of detection showed that the impact of blasting vibration on the nearbybuildings is less than the permissible vibration value stipulated by safety regulationsfor blasting practices and thus ensured the safety of the surrounding houses.4）The practice of the project proved that on the deep-water conditions blastingcompaction method to deal with soft soil foundation can reach the comprehensivegoal of being safe, reliable and economic. The corresponding technology can be usedto promote the deep soft soil reclamation projects, port projects and other mainprojects.