基于棉花秸秆排水体的吹填淤泥真空预压试验研究

Experimental Study on Vacuum Preloading of Dredger Fill Sludge Based on Cotton Straw Drainage Body

采用棉花秸秆代替传统真空预压法中的塑料排水板,对吹填土进行加固,通过棉花秸秆排水体真空预压模型试验,监测试验过程的真空度、排水量、沉降量和卸载后含水率等指标,考察该技术的可行性。试验结果表明:棉花秸秆排水体直径越大、密度越小,加固效果越好。当秸秆捆直径为45 cm,密度为0.0637 g/cm 3时,真空预压排水一段时间后,其真空度维持在90~100 kPa,累计排水量约120 L左右;稳定后的土体沉降量约30 mm。加固后土体含水率明显下降。以上结果均表明秸秆排水体能较好地加固吹填土。此外,棉花秸秆作为农作物废弃物和可降解材料,具有成本低廉、绿色环保等优势,该技术值得工程推广。

Cotton straw is used to replace the plastic drainage board in the traditional vacuum preloading method to strengthen the dredger fill.The vacuum preloading model test of cotton straw drainage water was carried out to monitor the vacuum degree,displacement,settlement and water content after unloading.The feasibility of this technology is investigated.The test results show that the larger the diameter of cotton straw drainage body is,the smaller the density is,and the better the strengthening effect is.When the straw bale diameter is 45cm and the density is 0.0637 g/cm 3,the vacuum degree is maintained at 90~100 kPa and the cumulative displacement reaches about 120 L after a period of vacuum preloading drainage.The soil settlement amount after stabilization is about 30mm.The soil moisture content decreased obviously after reinforcement.All the above results show that straw drainage can effectively reinforce dredger fill.In addition,as a kind of crop waste and degradable material,cotton straw has the advantages of low cost and environmental protection,which is worthy of engineering promotion.