广州南沙地区软土采用水泥和粉煤灰固化试验研究

Experimental Study on Cement&Fly Ash Solidification of Soft Soil in Nansha Area,Guangzhou

通过室内试验,研究广州市南沙地区软土采用水泥和粉煤灰加固力学特性。考虑水灰比、水泥粉煤灰混合固化剂掺量、粉煤灰掺量的变化对固化土无侧限抗压强度的影响,建立固化土强度-龄期一系列函数公式。研究显示:水泥起到提高固化土强度的主要作用,粉煤灰的掺量应有所限制;对于不同的混合固化剂配比,有各自的最佳水灰比。水灰比小于0.5,加大混合固化剂掺量不能显著提高固化土强度。广州南沙软土采用水泥粉煤灰搅拌桩加固,混合固化剂掺量取15%~18%,粉煤灰掺量取20%~30%,水灰比取0.53左右,比较合理。

Through the laboratory test,the mechanical properties of the soft soil in Nansha area of Guangzhou strengthened by cement&fly ash are studied.Considering the influence of water cement ratio,cement fly ash admixture and fly ash admixture on unconfined compressive strength of sol idif ied soi l,a series of functional formulas of strength age of solidified soil are established.The results show that cement plays an important role in improving the strength of solidified soil,the amount of fly ash should be limited,and the best water cement ratio for different mixture ratio of solidified agent.When the water cement ratio is less than 0.5,the strength of the solidified soil cannot be significantly improved by increasing the content of the mixture.Nansha soft soil in Guangzhou is reinforced by cement fly ash mixing pile.The amount of mixed curing agent is 15%~18%,the amount of fly ash is 20%~30%,and the water cement ratio is about 0.53,which is reasonable.