مقاله انگلیسی رایگان در مورد رفتار فونداسیون شمعی تحت بارهای محوری چرخه ای – اسپرینگر ۲۰۱۷

The bearing capacity analysis and settlement calculation of rigid pile composite foundations under embankment loads are hot issues in the field of geotechnical engineering, whose relevant theoretical study is becoming mature and gradually applied in engineering practice. It is worth noting that most of the theoretical analyses assume that embankment loads are static loads, and the dynamic properties of traffic moving loads are not considered fully. Obviously, during the operation period, the rigid pile composite foundation of expressway embankment should bear not only the dead load generated by the embankment deadweight, but also the cyclic dynamic loads of the periodic vehicle driving. As a result, the research of soil dynamic properties and interaction mechanism of pile-soil under the premise of cyclic dynamic loads will be another key to research the bearing capacity and settlement calculation of the rigid pile composite foundation under traffic moving loads. Under the long-term dynamic loads, the deformation property of soil appears as accumulated deformation mainly. Scholars put forward computational and empirical expressions of all kinds of accumulated deformations specifically through the cyclic triaxial test and the research of model test. The representative achievements include: the traditional index model through indoor model tests based on the consideration of the effect of dynamic strength of soil has been improved [1]; on this basis, the effect of initial stress field has been taken into consideration [2]; the effect of the residual stress on the soil accumulated deformation has been analyzed in detail [3]; the semilogarithm relationship between attenuation index and cycle times has been proposed [4]; CHEN et al [5] systematically researched the bearing and deformation behavior of the rigid pile of saturated silt foundation through a series of large scale model tests; POULOS [6, 7] made a series of theoretical researches and experimental investigations about the cyclic weakening property of bearing capacity of pile foundations, and established the empirical formula of the attenuation of bearing capacity along with cycles of axial loads; a series of 1 g model tests to research the longterm mechanical behavior of marine fan foundation in saturated soft clay foundation under cyclic loads have been made, which discovered that after the dynamic load, the soil around pile weakened obviously [8]. The numerical software is adopted to simulate the actual working conditions of the pile foundation under embankment. Under the action of vertical cyclic loading, the pile foundation attends to the attenuation of the bearing capacity and stiffness and increasingly forms cumulative settlement [9–۱۱]. After the comparison with the results of dynamic model test, its accuracy was verified, and then, the second development platform of ABAQUS was used to introduce the soil attenuation factor.