By conducting field loading tests of single piles and composite foundation with single pile、four piles、nine piles in different length and area displacement ratio about rammed soil-cement pile composite foundation,the influence of pile length and area(displacement) ratio on bearing capacity、stress ratio between pile and soil、concentration coefficient of pile stress、reducing coefficient of soil stress between piles are studied.
(3) Plane finite element method (FEM) is introduced to investigate bearing mechanism of rigid pile composite ground under embankment. Soil arching effect, membrane effect and pile stress concentration are highlighted, and the role of pile cap in the composite ground is analyzed.
The stress ratio between pile and earth in composite ground,concentration coefficient of pile stress,reducing coefficient of earth stress between piles are analyzed in association with loading test of the composite ground,field measured reaction of pile tip,reaction of earth between piles. The properties of shared loads between pile and earth in composite ground are also studied.
With multi pan single pile composite foundation as a calculation model and with three dimension non linear finite element to calculate the pile stress and the earth stress between piles in the multi pan cement soil composite foundation,some difficult to obtained in site results were obtained. The paper summarized the stressed characteristics of the multi pan cement soil pile foundation.
From these data, the paper analyzes the variation regularities of the pile-soil stress ratio,the load sharing ratio of pile and soil,the stress concentration coefficient and the stress reduction coefficient of pile body and inter-pile soil.
The pile is analyzed by ANSYS software, which is largely used in the world, to contrast the settlement of the pile head between precast concrete screw pile and traditional pile under the same conditions;
In this paper, based on a large amount of on-the-spot detecting data,the features of reflection waves corresponding to various kinds of structural defects detected by the Pile Integrity Tester are summarized,and it is pointed out that the types of defects should be judged through comprehensive analysis according to the stress wave transmission and reflection theory.
Using indoor physical modeling of composite subgrades un der flexible foundation, the earth pressure between piles, the axial stress of p iles and the stress at pile top are measured, for various scenarios. The results indicate: (1) the axial force of pile within a depth of two times of the pile d iameter below the foundation essentially remains constant, while for the rest of the effective pile length, the stress decreases with depth;
In this paper,the author analyzes on pile-stress,stress of soils between piles and displacement of piles using Ansys. The conclusion is that the bearing capacity is increased by 40% with branches,pile-side friction is about 90% of single-pile bearing capacity,first branch bears most loads,bearing capacity varies with the numbers of branches,diameters of branches,intervals of branches and elastic modulus of piles.
By the analysis of triaxial test results of stone pile models with different gradation,this paper noticed the similarityr between pile stress strain relation under practising confining pressure level and Duncan Chang non linear model,and furthermore,discussed the effect of different confining pressure upon pile deformation properties and drew some conclusions that would enrich the design work.
The stress ratio between pile and earth in composite ground,concentration coefficient of pile stress,reducing coefficient of earth stress between piles are analyzed in association with loading test of the composite ground,field measured reaction of pile tip,reaction of earth between piles.The properties of shared loads between pile and earth in composite ground are also studied.