侵蚀影响下水泥土的力学性质试验研究

港珠澳大桥拱北隧道地处沿海地区，其地下水与海水相连，隧道基底采用粉体喷射搅拌法和高压喷射注浆法等方法进行加固，加固产生的水泥土在海水侵蚀性离子作用下其强度和稳定性会发生变化，从而对工程安全产生影响。根据上述两种施工工艺，制作内部含侵蚀物质和不含侵蚀物质的两种水泥土试块，配制多种不同浓度的单组分的化学溶液来模拟海水侵蚀环境，将制备的水泥土试块置于侵蚀溶液中进行预定时间的短时（≤28 d）浸泡，通过无侧限抗压试验、电镜扫描以及离子色谱测定，分别得到了单组分侵蚀溶液短时浸泡下水泥土试块无侧限抗压强度、微观结构随侵蚀溶液浓度和侵蚀时间的变化规律，以及侵蚀环境中离子浓度随侵蚀时间的变化规律。基于海水化学成分，配制多种不同浓度的双组分的化学溶液来模拟海水侵蚀环境，将制备的内部含侵蚀物质的淤泥质土水泥土试块置于侵蚀溶液中进行预定时间的长时（≥90 d）浸泡，通过无侧限抗压试验得到了双组分侵蚀溶液长时浸泡下水泥土试块无侧限抗压强度变化规律。试验结果可为临时性及长期性水泥土工程的设计及安全维护提供一定参考依据。

Experimental study of mechanical properties of cemented soil under corrosion influence

Hong Kong-Zhuhai-Macao Bridge Gongbei tunnel is located in coastal areas. Its groundwater is connected to the seawater, foundation pit bottom of Gongbei tunnel is reinforced by dry jet mixing method and high pressure jet grouting method. Under the action of corrosive ions in seawater, strength and stability of cemented soil produced by reinforcement would get changed; thus impact on engineering safety. According to difference between the two kinds of construction technology，two kinds of cemented soil test blocks which contain or not contain corrosive substance were made, one-component chemical solutions of different concentrations were prepared to model water erosion environment, then the prepared cemented soil test samples were put into the corrosive solution to soak for scheduled short period (≤28 d). By unconfined compression test, SEM and ion chromatography test, change laws of microstructure and unconfined compression strength of cemented soil test samples with corrosion time and solution concentration after short period soaking in one-component erosion solution; change law of ion concentration in corrosion solution with corrosion time was obtained respectively. Based on chemical component of brine, two-component chemical solutions of different concentrations were prepared to model water erosion environment; then the prepared containing corrosive substances mucky cemented soil test samples were put into the corrosive solutions to soak for scheduled long period(≥90 d). By unconfined compression test, change laws of unconfined compression strength of cemented soil test samples with corrosion time and solution concentration after long period soaking in two-component erosion solutions were obtained. These offer reference frame for temporary and long-lasting cemented soil engineering design and safety maintenance.