Abstract:Water-enriched sand layer will bring difficulty for grouting and therein result in failure of grouting. The influence of the seawater increases the difficulty of grouting. This paper presents grouting in water-enriched sand layer of the first subsea tunnel—Xiamen Xiang¢an subsea tunnel,China. Drilling and pushing water are used to check the grouting result. Some grouting rules are obtained and some parameters such as grouting amount,grouting pressure,grouting speed and diffusion radius are suggested. This paper also finds the results of an experimental investigation applied to the study of the effects of seawater. The result indicates that the seawater will delay the time of initial setting,slowing down the speed of gain in strength,diluting the density of slurry and aggravating differential pervasion of grouting. Several problems of grouting in seawater are discussed from the test and the construction experiences of Xiamen Xiang¢an subsea tunnel. The study can provide instructional advice for both design and construction of grouting of the Xiang¢an subsea tunnel. Meanwhile it can also provide important reference to similar project.