曹妃甸区固化吹填土的固化机理及其工程性质

Engineering properties and solidification mechanism of solidified dredger fill in Caofeidian Area

在对曹妃甸区吹填土进行了室内物理化学性质检测的基础上,测试研究了三种固化吹填土的工程性质,探讨了养护龄期、Na2SiO3掺比、PAM的掺比3个控制因素对吹填土工程性质影响的显著性水平,并从微观角度揭示了固化机理.研究结果表明:曹妃甸区吹填土为细粒土(粉土),级配不良土,成分以石英为主,并含有一定量黏土矿物;PAM+Na2SiO3固化吹填土的工程性质要好于Na2SiO3固化吹填土和PAM固化吹填土;对吹填土工程性质影响的显著性水平由强到弱依次为养护龄期、Na2SiO3掺比、PAM掺比;PAM在吹填土颗粒间产生吸附作用和架桥作用,Na2SiO3在土颗粒间产生吸附作用并与土体发生化学反应.在两种固化剂的联合固化作用下,吹填土可获得更好的工程性质.

Based on the indoor physical and chemical properties of dredger fill in Caofeidian area,the engineering properties of three kinds of solidified dredger fill were tested and studied.The significance of three curing factors,such as curing age,Na2SiO3 mixing ratio and PAM ratio,on the engineering properties of dredger fill were discussed,and the curing mechanism was revealed from a micro perspective.Results show that the dredger fill in Caofeidian area is fine-grained soil(silt),poorly graded soil,with quartz as the main component and a certain amount of clay minerals.The engineering properties of PAM+Na2SiO3 solidified dredger fill are better than Na2SiO3 solidified dredger fill and PAM solidified dredger fill.The significant level of influence on the engineering properties of dredger fill from strong to weak is curing age,Na2SiO3 incorporation ratio and PAM incorporation ratio.PAM adsorbs and bridges between dredger fills,Na2SiO3 adsorbs between soil particles and reacts with soil chemically.Under the combined solidification of two solidifying agents,dredger fill can obtain better engineering properties.