聚氨酯固化钙质砂物理力学特性  

Indoor Physical and Mechanical Properties of Polyurethane Cured Calcareous Sand

作　　者：王智超[1,2] 彭柱 彭峰 闫实 WANG Zhi-chao;PENG Zhu;PENG Feng;YAN shi(Hunan Key Laboratory of Geomechanics and Engineering Safety,Xiangtan University,Xiangtan 411105,China;School of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China;China Construction Fifth Engineering Division Corp.,Ltd.,Changsha 410000,China)

机构地区：[1]湘潭大学岩土力学与工程安全湖南重点实验室,湖南湘潭411105 [2]湘潭大学土木工程学院,湖南湘潭411105 [3]中国建筑第五工程局有限公司,长沙410000

出　　处：《长江科学院院报》2024年第1期107-113,共7页Journal of Changjiang River Scientific Research Institute

基　　金：湖南省教育厅重点和优秀青年项目(23A0141,17B260);湖湘高层次人才聚集工程——创新团队项目(2019RS1059)。

摘　　要：聚氨酯加固是一种新型环保快速的土质改良方法。针对南海钙质砂采用聚氨酯快速改良,并通过室内试验验证该处置方法的有效性和适用性。通过对聚氨酯固化钙质砂试样开展无侧限抗压强度试验、静力荷载和循环荷载下的三轴试验以及渗透试验,研究聚氨酯固化钙质砂的最佳凝胶时间,静、动强度特性及渗透特性。试验结果表明:固化试样的最佳凝胶时间为6.5 h;随着掺量的增加,固化钙质砂黏聚力得到显著提高,内摩擦角基本保持不变,在海水环境养护下的聚氨酯钙质砂仍然保持了较高的强度;随着掺量的增加,聚氨酯钙质砂的初始动剪切模量增加,最大阻尼比降低;钙质素砂渗透系数的数量级为10^(-6),掺入2%~10%聚氨酯后数量级降至10^(-8)~10^(-7),聚氨酯补漏效果较好。Polyurethane improvement is a novel,eco-friendly,and rapid method for soil improvement.This study aims to evaluate the effectiveness and applicability of polyurethane rapid improvement for calcareous sand in the South China Sea.The optimal gelling time,static and dynamic strength,and permeability characteristics of polyurethane-cured calcareous sand were investigated through unconfined compressive strength tests,static and cyclic load triaxial tests,and permeability tests.The obtained results encompass both mechanical and permeability properties.Notable findings include:1)the optimum gelling time for the cured samples is 6.5 hours.2)The cohesion of the cured calcareous sand significantly improves with increasing polyurethane content,while the internal friction angle remains relatively unchanged.The polyurethane calcareous sand cured in sea water maintains a high strength.3)Increasing the polyurethane content leads to an increased initial dynamic shear modulus of the calcareous sand,but a reduced maximum damping ratio.4)The permeability coefficient of the calcareous sand ranges around 10^(-6).However,upon adding polyurethane(2%-10%),this value decreases to 10^(-8)-10^(-7),demonstrating a remarkable sealing effect of polyurethane.

关 键 词：钙质砂 聚氨酯 凝胶时间 力学特性 渗透系数 

分 类 号：TU443[建筑科学—岩土工程]