One type of problematic soil in geology and geotechnical engineering recognized as collapsible soils can withstand relatively high pressure in an unsaturated state. The constant stresses because of soil saturation leading to a large volume reduction in the partially saturated condition are a matter of issue for the infrastructures constructed in the regions containing these soil types. As one of the environmentally friendly materials and potential stabilizers, nano-silica can be used to treat collapsible soils. The present study investigates the nano-silica effect on the soil collapse treatment in the Sivand region, Fars Province, Iran. A set of laboratory tests, including grain size analysis, Atterberg limits tests, water content, sand equivalent test, proctor and modified proctor tests, normal and double consolidation tests, were performed to determine the soil sample’s geotechnical characteristics. The consolidation test was then carried out on soil samples without nano-clays, reconstructed with 11% moisture content using static compaction methods to show the increasing nano-silica additive from 1 to %5 will obtain the less collapse index. The tests have also done on samples made using the mixture of soil, and nano-silica indicated the swelling of samples after saturation. Test results have shown that the saturation pressure and nano-silica content have direct and indirect relations with the strain of collapsible soils. The extracted test results are used as a database to develop an efficient model to predict reconstructed samples’ strain. Additionally, the parametric and sensitivity analyses confirm the model output with the test results.

地质学和岩土工程中的一种问题土壤被认为是可塌陷的土壤，可以在非饱和状态下承受相对较高的压力。由于土壤饱和导致在部分饱和条件下体积大量减少的恒定应力是在包含这些土壤类型的地区建造的基础设施的问题。作为一种环保材料和潜在的稳定剂，纳米二氧化硅可用于处理湿陷性土壤。本研究调查了纳米二氧化硅对伊朗法尔斯省 Sivand 地区土壤塌陷处理的影响。一组实验室测试，包括粒度分析、Atterberg 极限测试、含水量、砂当量测试、proctor 和修改 proctor 测试、正常和双重固结测试，用于确定土壤样品的岩土特性。然后在没有纳米粘土的土壤样品上进行固结试验，使用静态压实方法以 11% 的含水量重建，表明纳米二氧化硅添加剂从 1 增加到 5% 将获得更小的坍塌指数。还对使用土壤混合物制成的样品进行了测试，纳米二氧化硅表明样品在饱和后会膨胀。试验结果表明，饱和压力和纳米二氧化硅含量与湿陷性土的应变有直接和间接的关系。提取的测试结果用作数据库来开发有效的模型来预测重建样品的应变。此外，参数和灵敏度分析通过测试结果确认了模型输出。