变径水泥土搅拌桩加固桥头软基的试验分析

变径水泥土搅拌桩是一种新型的水泥土搅拌桩技术,它针对传统水泥土搅拌桩的弊端进行了改进,取得了良好的工程效果.介绍了变径水泥土搅拌桩在高速公路桥头软基的应用情况,并对其施工机械和施工工艺进行了详细说明.试验结果表明,变径水泥土搅拌桩保证了桩体中的水泥掺入量,提高了水泥浆分布的均匀性,从而保证了桩身质量,特别是深部桩体的质量;28 d龄期桩体的强度和均匀性较7 d均有较大提高;桩身水泥土芯样的电阻率与其强度之间存在着较好的线性相关关系;在其他试验条件相同时,扩大头高度越高,变径搅拌桩的单桩极限承载力越高;在保证质量的同时,变径水泥土搅拌桩能相对节约了工程成本,经济效益明显.

Experimental study of T-shaped soil-cement deep mixed column in soft subsoil treatment

T -shaped soil-cement deep mixed column is a new type of sof t soil foundation t reatment method. Since special modif icat io ns have been made tow ar ds tho se drawbacks w hich exist in tr aditional deep mix ed co lumns, the T-shaped soil-cement deep mix ed co lumn ex hibit s g ood performance and thus has been w idely used recent ly . The applicat io n pract ice o f T -shaped soil-cement deep mix ed column in sof t foundat io n at bridge head w as briefly described. The corresponding const ruct ion equipment s and techniques w er e explained in detail. T he result s show that the st reng th of the co lumn adopted bidirect ional mixed technique is uniform, that the soil cement w ith longer curing t ime is more homogeneo us and has higher st reng th, and that there exists a goo d linear r elat ionship between the strength and the electr ical resistivity . As a result , the st reng th of the cor e samples can be evaluated from their elect rical resist ivity. The leng th of the upper co lumn part increased under the same condit ion w ith the bearing capacity o f the single column. T -shaped so il-cement deep mixed column has the superior eng ineer ing characterist ics and cost-effect ive in the so ft subsoil t reatment .