Numerical Simulation And Engineering Application Of Straw System Under Vacuum Preloading Drainage

With the increase of the coastal development process,in the construction of coastal soft soil area,the disposal of mud,mud flow is a common problem of ultra soft soil,reclaimed for mud to mud flow ultra soft soil,bearing capacity is almost 0,personnel and machinery can not approach.In the face of such super soft soil foundation,the method of shallow layer reinforcement and deep treatment is often used.Shallow reinforcement often used in natural drying method,chemical curing method,vacuum preloading method etc..Deep treatment of deep piling or deep mixing methods.On the other hand,rural crop straw disposal has become a very tough problem to solve Chinese environmental protections.Taking into account the above factors,this paper puts forward the unnecessary straw as drainage material instead of sand cushion and plastic drainage plate,.The new-type drainage system with the unwanted straws are able to consolidate and treat sludge with high amount water by the vacuum aspiration in the construction of coastal engineering,to achieve the aim of waste control by waste.With cotton straw and Dongtai engineering produced in the ultra soft soil as the research object,through laboratory test,model test,numerical analysis and field test methods of straw permeability,new straw drainage system consolidation treatment effect of the ultra soft soil and the factors influence the development of the system the study puts forward the application of complete sets of technology,summarized as follows:(1)By the model test and numerical simulation research of consolidation drainage performance of the straw rolls,it reveals the influence law of diameter,density,distance,arrangement of the straw rolls on consolidation drainage effect(2)By using the finite element software ABAQUS,the numerical simulation analysis is carried out to study the performance of the key design parameters.Through clearing straw roller diameter,density,distance,ratio and arrangement on the comprehensive effect of consolidation drainage effect,the team calculates and obtains that the main factors influencing the consolidation effect is distance and diameter of the straw roll?(3)Based on field application research,the team develops by oneself convenient and efficient straw roll producing devices,proposes construction method of straw roll drainage system,the construction process includes straw roll producing and driving,straw mat producing and laying,vacuum drainage auxiliary system connecting and sealing membrane layout.In the end,the study forms a complete set of the new-type straw drainage consolidation treatment technology for the ultra soft soil with high amount water.(4)The field test research verifies that the consolidation effect of the new straw drainage system is advantageous,calculation model is feasible,and optimization method is put forward.At the same time,application technology of new-type straw drainage system consolidating dredger fill with high amount water is better than that of the method on the design drawings,which of construction technology includes drying,mixing lime,crushing and backfilling,has the good social effect and application prospect.