Nowadays it is possible to find many experimental and analytical studies aimed for better prediction of sand soil response during the installation and loading stages of displacement pile. The interaction between the soil and the pile is very complex, this is the reason why it is not exhaustively described, so far. Response of the soil, especially the ultimate state necessitates investigate the nature of soil response via tip and shaft as well as their relation. Qualitative evaluation of the stress state influence on pile behaviour serves for more clear description of the soil ultimate response mechanism. Current investigation presents the results of two specific instrumented piles tests. The 1 st type of the tests revealed the shear and normal stresses distribution at particular areas of short displacement pile interface during static vertical load test. The 2 nd type of the tests showed the radial stresses increment paths in the soil during the pile installation stage. The performed tests of the short displacement piles results cleared, that during the static load tests the highest shear stresses, on the pile skin, get concentrate near the pile tip and during the installation stage the radial stresses significant increase when pile tip gets near the push in load cells measurement plane.

Statyba Civii Engineering KÜGINIO STIPRIO IR GILIOJO SPRAUSTINIO PAMATO PAGRINDO LAIKOMOSIOS GALIOS BANDYMU, TAIP PAT KITAIS METODAIS NUSTATYTy DEFORMACIjy MODULiy PRIKLAUSOMYBÈS Tautvydas Statkus^ Váidas MartinkusV ilniaus Gedimino technikos universitetas El. pastas: 'Tautvydas.Statkus@vgtu.lt; ^Váidas.Martinkus@dohvgtu.ltSantrauka. Sio straipsnio tikslas yra nustatyti priklausomybes tarp gmnto kflginio stiprio ir grunto deformaeijii moduliij, gautii i § giliojo pamato pagrindo laikomosios galios bandymii duomenii, taip pat gmnto tyrimo [spraudziamaisiais horizontaliojo slégio matuokliais bei kompresiniu aparatu. Straipsnyje pateiktos tiriamojo orasausio smèlinio grunto fizinès ir mechaninés savybès nustatytos laboratoriniais ir lauko tyrimo metodais. Atlikus regresinç bandymii duomenii analizç straipsnio isvadose pateiktos minètii dydziii priklausomybes. Tydmo duomenys gali bûti panaudoti sudarant praktini metod^ giliqjil spraustiniii pamani smèliniii pagrindii nuosèdziams prognozuoti.© Vilniaus Gedimino technikos universitetas

One can find lot of the methods and theories to determine and interpret the nature of the bearing capacity of displacement piles in cohesion-less soil. The presence of many methods leads to the variety of results and yields that no general and relevant methods have been proposed yet. Many experimental investigations do not fit properly the results of known numerical simulations. These simulations yield that the shear stress near the end of the pile increases significantly, when compared with the rest of pile length. Current investigation presents the specific test results of the short displacement pile under vertical load in cohesion-less soil. The full scale test was performed and the vertical stresses beneath base and shear stresses along the pile have been measured, as a result the shear stress significant increase near the end of the pile was observed. The obtained results can be used for developing the shaft and tip bearing capacity evaluation method for the short displacement piles in cohesion-less soil.

In this article jacked pile installation technology and its current processes, altering the base physical and mechanical characteristics are discussed. For the jacked pile static load test simulation Plax 3D software was selected, the opportunities and developments were described. Model building, materials, models, model geometry, finite elements, boundary conditions and assumptions adopted in addressing problems described in detail. Three different tasks formulated and load-settlement dependence a comparison of the results with the experiment given. Conclusions are formulated according to the modeling results. Šiame straipsnyje aptarta spaustinių polių įrengimo technologija ir ją taikant vykstantys procesai, keičiantys pagrindo fizines ir mechanines charakteristikas. Spaustinio polio bandymui statine apkrova modeliuoti pasirinktas PLAXIS 3D programinis paketas ir aprašytos jo galimybės bei raida. Detaliai nupasakotas modelio kūrimas, medžiagų modeliai, modelio geometrija, baigtiniai elementai, kraštinės sąlygos ir priimamos prielaidos sprendžiant problemą. Suformuluoti trys sprendžiami uždaviniai ir apkrovos bei nuosėdžio priklausomybe pateikiamas rezultatų palyginimas su eksperimentu. Atsižvelgiant į modeliavimo rezultatus suformuluotos išvados.

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