Research On Microstructure And Mechanical Mechanisms Of Dredger Fill At The Initial Stage Of Settlement Consolidation In The Binhai New Area, Tianjin

Hydraulic fill method has made important contribution. in the coastal city, Butthe newly dredger mucky soil has a few adverse conditions,such as high liquid limit,high water content, high compressibility, low permeability. On the other hand, as akind of artificial soil natural deposition, dredger fill apparently be part of structuredsoils, which has the structural characteristics of typical. The soil structural isinfluenced by the microstructure in essence. We should consider its micro structure,when we are considering processing blowing time fill foundation. This paper aims isto reveal the rule of the microstructure evolution and blow strength increasing ofdredger fill at the beginning of consolidation below self-weight, reveal therelationship between soil strength growth and microstructure evolution, abolish aquantitative relationship between the structural strength and micro structureparameters, establish a effective microstructure mechanics model. Finally, provide aeffective method to calculating and predicting the strength of flowing dredger fill atthe early stage of settlement consolidation.The research of this paper includes the following aspects:1. Analogue the test of scene using large test box, let the soil consolidate in theself-weight stress. Determinate the total strength, remolded strength and structuralstrength of dredger fill blowing self-weight at initial stage of consolidation. Strengthgrowth period is from96hours to320hours after hydraulic filling.2. Obtaining the soil samples which were in the soft-flow plastic state Usingfrozen sampler. in simulation test. Observe the micro structure of the dredger fill bycombining the Mercury injection and scanning electron microscopy. The soil can beviewed as a horizontal isotropic body at the beginning of consolidation. Mercuryinjection data shows that there are three groups of dominant pore which respectivelycorresponding to the corresponding stable microstructure in the samples.3. Handle the image of the SEM using the soft of Photoshop and MATLAB.Determinate many kinds of micro structure parameters. The parameters most closelyrelated to strength growth include porosity, pore area, pore size and the directional ofstructure element.4. Analyze the microstructure parameters contact with strength growth characteristic at beginning of consolidation. Explain strength development mechanismof the dredger fill at beginning of consolidation. The strength growth is the result ofthe soil structure evolution. This evolution is unbroken, but not uniform, showing aterraced evolution from larger pore to smaller pore.5. Establish a mechanism model based on the elements of the process porosityEj(h) and time factor k(h). Verify feasibility of computational strength of blowing thedredger fill by the process porosity Ej(h) and time factor k(h).