珠三角软土原位测试的工程实践及成果应用效果分析

为了扩大原位测试技术在珠三角软土工程中的应用和验证用十字板剪切试验推算软土的抗剪强度指标计算方法的可行性,以珠海某软土填方边坡和广州南沙某基坑工程中软土原位测试与工程应用为例,开展了原位测试结果与室内指标的对比分析和成果应用效果分析。结果表明:原位测试能较好地反映软土的实际状态,用十字板剪切试验推算的软土抗剪强度参数值大于室内土工试验得到的参数值;在珠三角地区用《港口工程地基规范》( JTS 147-1—2010)中附录J方法推算得到的软土的黏聚力偏大,超出经验范围值,所以尚不宜直接用于工程设计。建议进一步对原位测试数据的应用开展相关理论研究,以扩大应用范围。

In-situ Test of Soft Soil in Pearl River Delta: Engineering Practices and Effect Analysis of Result Applications

In order to expand the application of in-situ testing technology in soft soil projects in the Pearl River Delta and to verify the feasibility of using cross plate shear test result to calculate the shear strength of soft soil, we compared in-situ test results with indoor test results, and analyzed the application effects. We took the in-situ test and its engineering application in a soft soil fill slope in Zhuhai and a foundation pit engineering in Nansha, Guangzhou as engineering examples. Results unveil that in-situ test could well reflect the actual state of soft soil, and the shear strength parameter of soft soil calculated via vane shear test result is greater than those obtained by laboratory soil test. However,in Pearl River Delta region, the cohesion of soft soil calculated by method in Appendix J of Code for Foundation of Port Engineering(JTS 147-1—2010) exceeds empirical range, hence is not suitable for direct use in engineering design. We suggest that further theoretical research on the application of in-situ test data should be conducted to expand its application scope.