Tension tests on smooth and rough model piles in dry sand
Tension tests on smooth and rough model piles in dry sand
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DOI：
10.1139/cgj-36-4-746
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发表时间：
1999-08-01
影响因子：
3.6
通讯作者：
Al-Deeky, H
中科院分区：
文献类型：
--
作者：
Alawneh, AS;Malkawi, AIH;Al-Deeky, H
为了描述影响干砂中桩的最终抗拔轴阻力的重要变量，对两种尺寸（外径41和61 mm）的开放式和封闭式粗糙和光滑模型桩进行了包括64次拔出试验的测试程序。模型桩安装在中密和密砂中，埋深为0.8 m，采用两种沉桩方法，静压和打桩。使用尺寸为1.1 x 1.1 x 1.3 m的刚性钢箱作为砂容器。研究结果表明，沉桩方法、初始砂层条件、桩面粗糙度、桩端类型等因素对干砂层中单桩的极限抗拔桩侧阻力均有显著影响（从大到小）。整体而言，封闭式桩表现出的侧阻力增加24%，与开放式桩相比，打入模型桩的平均单位侧阻力是在密实砂条件下的静压模型桩的1.33倍，是在中密实砂条件下的静压模型桩的1.52倍。根据测试变量，本研究中测试的粗糙模型桩与光滑模型桩相比，承载力增加了12-54%。粗糙模型桩的侧土压力系数值大于光滑模型桩。这表明，由于桩表面粗糙度的能力增加的一部分是由于在拉伸加载过程中的径向有效应力的增加。
In order to delineate the significant variables affecting the ultimate uplift shaft resistance of a pile in dry sand, a testing program comprising 64 pullout tests was conducted on open- and closed-ended rough and smooth model piles of two sizes (41 and 61 mm outside diameter). The model piles were installed in medium dense and dense sand to an embedded depth of 0.8 m using two methods of pile placement, static jacking and driving. A rigid steel box measuring 1.1 x 1.1 x 1.3 m was used as a sand container. The results obtained from this study indicated that pile placement method, initial sand condition, pile surface roughness, and pile end type are all significant variables (given in descending order) affecting the ultimate uplift shaft resistance of a single pile in dry sand. Overall, the closed-ended piles showed a 24% increase in shaft resistance compared with the open-ended piles and the average unit shaft resistance of the driven model pile was 1.33 times that of the jacked model pile in the dense sand condition and 1.52 times that of the jacked model pile in the medium dense sand condition. Depending on the test variables, the rough model piles tested in this study experienced a 12-54% increase in capacity compared with the smooth model piles. Also, the lateral earth pressure coefficient values for the rough model piles were greater than those for the smooth model piles. This suggests that part of the increase in capacity due to pile surface roughness is attributed to an increase in the radial effective stress during tensile loading.