The present article assesses the potential use of piled raft foundations for settlement control in grain silos, by performing numerical analyses with instrumented structures built in a particular city of the Mato Grosso state, deep in the Brazilian agricultural frontier. In this city, eight steel grain silos were constructed, and settlements were topographically monitored. The silos were numerically back analyzed using a finite-element-based hybrid numerical tool to verify interactions influence between the isolated (unpiled) foundation rafts during the grain storage season. A parametric analysis was subsequently carried out to verify the potential use of piled rafts to decrease settlement, as well as to improve design in terms of a better configuration concerning the use of compacted soil layers beneath the raft, raft thickness and pile length, and disposition within the foundation system. The numerical analyses indicated the use of a piled raft arrangement with a geometric factor equals to 0.09 as a proposed optimized solution aiming to minimize differential and total settlements. From this arrangement onwards, changes in pile spacing, pile diameter or in the number of piles, leading to higher geometric factors, were not able to provide significant settlement reductions. The increase in raft thickness and the use of compacted soil layers do not contribute to major improvements in the foundation settlement. The alternative optimized solution was able to ensure the serviceability and safety requirements of the silos, which can serve as a design benchmark.

中文翻译：

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可塌陷土钢粮仓沉降控制桩筏基础数值分析

本文通过对在巴西农业前沿深处的马托格罗索州特定城市建造的仪器结构进行数值分析，评估了桩筏基础在粮仓中沉降控制的潜在用途。在这个城市，建造了八个钢粮筒仓，并对聚落进行了地形监测。使用基于有限元的混合数值工具对筒仓进行数值回溯分析，以验证粮食储存季节期间隔离（未打桩）基础筏之间的相互作用影响。随后进行了参数分析，以验证桩筏的潜在用途，以减少沉降，以及在有关筏下压实土层的使用、筏厚度和桩长的更好配置方面改进设计，和基础系统内的配置。数值分析表明使用几何因子等于 0.09 的桩筏布置作为建议的优化解决方案，旨在最大限度地减少差异和总沉降。从这种安排开始，桩间距、桩直径或桩数量的变化导致更高的几何因素，无法显着减少沉降。筏板厚度的增加和压实土层的使用无助于地基沉降的重大改善。替代优化解决方案能够确保筒仓的适用性和安全性要求，可作为设计基准。数值分析表明使用几何因子等于 0.09 的桩筏布置作为建议的优化解决方案，旨在最大限度地减少差异和总沉降。从这种安排开始，桩间距、桩直径或桩数量的变化导致更高的几何因素，无法显着减少沉降。筏板厚度的增加和压实土层的使用无助于地基沉降的重大改善。替代优化解决方案能够确保筒仓的适用性和安全性要求，可作为设计基准。数值分析表明使用几何因子等于 0.09 的桩筏布置作为建议的优化解决方案，旨在最大限度地减少差异和总沉降。从这种安排开始，桩间距、桩直径或桩数量的变化导致更高的几何因素，无法显着减少沉降。筏板厚度的增加和压实土层的使用无助于地基沉降的重大改善。替代优化解决方案能够确保筒仓的适用性和安全性要求，可作为设计基准。桩直径或桩数导致更高的几何因素，无法显着减少沉降。筏板厚度的增加和压实土层的使用无助于地基沉降的重大改善。替代优化解决方案能够确保筒仓的适用性和安全性要求，可作为设计基准。桩直径或桩数导致更高的几何因素，无法显着减少沉降。筏板厚度的增加和压实土层的使用无助于地基沉降的重大改善。替代优化解决方案能够确保筒仓的适用性和安全性要求，可作为设计基准。