Experimental Research On The Work Mechanism Of Squeezed Branch Pile Based On Digital Image Correlation Method

The squeezed branch pile is an advanced new-type pile foundation which developed from the ordinary filling pile at the beginning of the 1990s. The advanced pile squeezes soil around pile to form branches or plates with a hydraulic squeezed machine, and thus gets its name. The branches and plates enlarge the surface of pile and change a part of friction resistance into end resistance, thus increase the bearing capacity of the pile. With such advantages as higher bearing capacity, less settlement deformation and lower pollution and so on, it has already been popularized gradually in many provinces and districts of our country now and gained much social and economic benefit.Because the late study and the complex bearing characteristics, it also remains many questions in the process of theory research and practical application to be worth discussing .Therefore ,whose thoroughly research on it's working principle has important theory significance and project application value on civil engineering foundation.Based on the principle of digital image correlation method (DIC), an analysis procedure of displacement is worked out, which is used to analyze the whole gradual deformation and destruction process of the Squeezed branch pile. And combined with numerical simulation analysis, the result of the experiment on the model is validated.The main conclusions include:(1) It's feasible. to apply Digital image correlation method (DIC) into the research on squeezed branch pile lateral soil displacement and working mechanism.(2) The squeezed branch pile's bearing capacity and it's capability against settlement are far better than that of the common pile. It is an ideal pile for the building or structure which has strict requirement for settlement.(3) The load transfer of the squeezed branch pile has obvious time and sequence effects. The roles the bearing disks play are unsynchronized.(4) The location, numbers, distance, diameter and other factors of the squeezed branch pile have influence on its vertical bearing capacity.(5) When the squeezed branch pile has high quality and the distance between the bearing piles are reasonable, its desruction is local shear destruction of soil under the bearing disk and punching destruction of the soil at the pile end.