养护压力对水泥固化高含水率淤泥强度的影响  

Experimental Investigation on the Effect of Curing Stress on the Strength of Cement Stabilized Mud at High Water Content

作　　者：郑少辉[1,2] 于同生[1] 章荣军 郑俊杰[1] ZHENG Shao-hui;YU Tong-sheng;ZHANG Rong-jun;ZHENG Jun-jie(School of Civil Engineering and Mechanics,Huazhong University of Science and Technology,Wuhan 430074,China;Fujian Academy of Buihting Research,Fuzhou 350028,China)

机构地区：[1]华中科技大学土木工程与力学学院,湖北武汉430074 [2]福建省建筑科学研究院,福建福州350028

出　　处：《土木工程与管理学报》2018年第5期115-121,133,共8页Journal of Civil Engineering and Management

基　　金：国家重点研发计划(2016YFC0800208);国家自然科学基金(51308241;51678266);中央高校基本科研业务费(2015TS118)

摘　　要：采用水泥固化疏浚淤泥(CSM)作为滨海交通设施(路基等)填料能同时解决疏浚淤泥弃置问题和理想填料(砂土料等)日益短缺的问题。随着高速交通设施的大规模兴建,CSM填筑高度越来越大,下部CSM将受到较大养护压力,此时CSM强度特性的演化其实是物理固结与水泥–水–黏土颗粒化学反应的耦合效应,这与固结压力作用下饱和软黏土强度发展机理存在本质区别,固结压力对CSM强度发展的影响尚不明确。本文基于室内试验,测试了不同配合比与养护压力工况下的CSM强度指标,评价了采用养护后孔隙比eot和有效孔隙比est作为基本指标来描述养护压力对CSM强度影响的适用性,并探讨了养护压力对CSM强度影响的内在机理。结果表明:养护压力对CSM强度特性影响显著; eot和est不能被用来定量描述养护压力pc对CSM强度的影响规律。由此推测养护压力对CSM强度影响的内在机理主要包括挤压固结效应和颗粒簇团间的"自锁"效应两个方面,并建立了表征养护压力效应的CSM的强度经验公式。An ideal solution for disposal of large volumes of unwanted dredged mud is to stabilize and use them as fill material for coastal embankment. This new kind of filling material（ referring to CSM from here on） can also resolve the sand scarcity issue encountered in embankment construction in coastal areas. With the rapid development of high-speed transportation,coastal CSM embankments become higher and higher,and as a result,the lower portion of CSM will suffer from high effective curing stress. The development mechanism of CSM strength under curing stress is totally different from that of saturated soft clay. The former involves both consolidation effect and chemical reaction effect while the latter only involves the consolidation effect. Hence,it＇s necessary to specifically identify the effect of curing stress on the mechanical properties of CSM. In this study,a series of laboratory tests is firstly conducted to acquire the unconfined compressive strengths quof CSM with different mixing proportions and various curing stresses. Then,the applicability of two basic parameters,i.e. after-curing void ratio eotand effective void ratio est,in describing the effect of curing stress on quis evaluated.Finally,the influencing mechanism of curing stress on quis studied. The results indicate that the curing stress has a significant influence on qu. However, both eotand estcannot be used to quantitatively describe the effect of curing stress on qu. It is speculated that the influence of curingstress on qumainly includes two components-the consolidation effect and the ＂self-locking ＂effect among the particle clusters.

关 键 词：水泥固化淤泥 养护压力 强度 孔隙比 固结效应 自锁效应 

分 类 号：TU443[建筑科学—岩土工程]