The lateral cyclic loaded piles’ behaviour in bonded residual soil is still poorly studied and understood by classical Geotechnics. Thereby, models are currently used to reproduce the behaviour of residual soils are based on those from other types of soils (unstructured), which results in a conservative design. Based on this, this paper proposes to evaluate the behaviour of three different shapes of steel piles embedded in bonded residual soil when submitted to cyclic lateral loading tests. These tests encompassed 10-mm displacements performed on the top of the piles [considering service (working) displacements]. The piles, with a length of 2.0-m, were equipped with strain gauges at 10 levels. The evaluated cross-sections have circular, square and H shapes, all with similar inertia moment and diameter/edge of 0.15-m. The effect of cyclic loading has shown a degradation of available lateral load, mostly in the first 30 cycles. This degradation is also seen at the bending moments obtained. The piles have also shown a short free-headed behaviour that rotates from a certain depth. Finally, the study showed that the square cross-section shaped pile had the best performance under service (working) cyclic displacements when embedded in bonded residual soil, followed by H cross-sectioned pile and finally the circular cross-sectioned pile.

中文翻译：

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轻黏性残余土中桩截面形状对钢驱动桩循环侧向响应的影响

经典土工技术对粘结残余土中的侧向循环荷载桩的性状仍然缺乏研究和理解。因此，当前使用的模型是基于其他类型土壤（非结构化）的模型来重现残余土壤的行为的，这导致了保守的设计。在此基础上，本文提出了在进行循环侧向荷载试验时，评估三种不同形状的埋入粘结残余土中的钢桩的性能。这些测试包括在桩的顶部进行10毫米的位移（考虑使用（工作）位移）。长度为2.0米的桩配备了10个水平的应变仪。评估的横截面具有圆形，正方形和H形，均具有相似的惯性矩和0.15-m的直径/边缘。循环载荷的影响已显示出可用横向载荷的下降，主要是在前30个循环中。在获得的弯矩处也可以看到这种退化。桩还表现出短时的自由奔放行为，从一定深度开始旋转。最后，研究表明，方形截面桩在埋入粘结残余土中时在服役（工作）循环位移下具有最佳性能，其次是H截面桩，最后是圆形截面桩。