發(fā)布時(shí)間：2018-04-14 10:08

  本文選題：敞口PHC管樁 + 樁土界面　； 參考：《建筑結(jié)構(gòu)學(xué)報(bào)》2017年05期

【摘要】：樁土界面剪切行為對(duì)靜壓敞口預(yù)應(yīng)力高強(qiáng)混凝土(PHC)管樁沉貫性狀及長(zhǎng)期承載力特性具有至關(guān)重要的作用。通過(guò)成層土地基中樁身預(yù)埋光纖光柵(FBG)傳感器的靜壓樁足尺試驗(yàn),分別對(duì)敞口PHC管樁貫入及靜載荷試驗(yàn)中的樁土界面剪切行為進(jìn)行研究。結(jié)果表明:在貫入階段,樁身軸力及側(cè)摩阻力沿樁的深度方向逐漸傳遞,傳力幅值與樁周土體性狀密切相關(guān),土層界面處軸力傳遞效率依次為98.2%、92.2%、96.3%、83.8%、80.5%。隨著壓樁循環(huán)次數(shù)的增加,同一深度土層摩阻力呈逐漸減小趨勢(shì)。經(jīng)歷5個(gè)壓樁循環(huán)后,深度6 m處的砂質(zhì)粉土層摩阻力減小幅度約為46.25%,深度10 m處的粉質(zhì)黏土層經(jīng)歷3個(gè)壓樁循環(huán)后摩阻力減小幅度約為12.1%;載荷試驗(yàn)過(guò)程中,樁側(cè)摩阻力隨著樁頂荷載施加自上而下逐步發(fā)揮。摩阻力完全發(fā)揮所需的樁土相對(duì)位移,粉質(zhì)黏土層的最大,約為6.96~7.46 mm,淤泥質(zhì)黏土層的次之,約為6.05 mm,砂質(zhì)粉土層的最小,約為4.23 mm;與原狀土相比,重塑區(qū)土體含水量、孔隙比參數(shù)指標(biāo)降低,重度、黏聚力及內(nèi)摩擦角增大。樁周重塑區(qū)土體物理力學(xué)指標(biāo)變化是貫入及載荷試驗(yàn)階段樁土界面剪切行為不同的重要原因。
[Abstract]:The shear behavior of pile-soil interface plays an important role in the penetrability and long-term bearing capacity of prestressed high-strength concrete (PHC) piles under static pressure.Based on the full-scale test of pile-embedded fiber Bragg grating (FBG) sensor in layered soil foundation, the pile-soil interface shear behavior of the open PHC pipe pile in the static load test and the penetration test were studied respectively.The results show that the axial force and lateral friction of the pile are gradually transferred along the depth direction of the pile at the penetration stage, and the amplitude of the transmission force is closely related to the soil properties around the pile. The axial force transfer efficiency at the interface of the soil layer is 98.22 / 92.2 / 96.3and 83.8 / 80.5 respectively.With the increase of pile cycle times, the frictional resistance of the same depth soil layer decreases gradually.After five pile cycles, the frictional resistance of sandy silt layer at 6 m depth decreases by 46.25, and the friction resistance of silty clay layer at 10 m depth decreases by about 12.1after three pile cycles.The side friction of pile is exerted gradually from top to bottom with the load on the top of pile.The relative displacement of pile and soil was brought into full play by friction resistance, the maximum of silty clay layer was 6.967.46mm, the second was silt clay layer (6.05 mm), and the minimum of sandy silt layer (4.23 mm), compared with undisturbed soil, the soil water content of remolded area was higher than that of undisturbed soil.The porosity ratio parameter index is decreased, the heavy degree, the cohesion force and the internal friction angle increase.The change of physical and mechanical indexes of soil in the remolded zone around pile is the important reason for the different shear behavior of pile-soil interface in the stage of penetration and load test.
【作者單位】： 中國(guó)海洋大學(xué)工程學(xué)院;南洋理工大學(xué)土木與環(huán)境工程學(xué)院;浙江理工大學(xué)建筑工程學(xué)院;青島理工大學(xué)土木工程學(xué)院;
【基金】：國(guó)家自然科學(xué)基金項(xiàng)目(51408439,41402275) 山東省住房和城鄉(xiāng)建設(shè)廳科技項(xiàng)目(KY048) 濰坊市科技發(fā)展計(jì)劃項(xiàng)目(2015GX012)
【分類(lèi)號(hào)】：TU473.11

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本文編號(hào)：1748832