中文摘要：

传统加固土体的方法主要是通过在土中加入一定量的高性能掺合剂使之成为一种强度较高的复合土体，但这种方法需要较长的养护时间，且不经济。利用一种新型实用的生物酶固化技术，针对香港地区3种常见的海洋黏土、完全风化花岗岩和完全风化凝灰岩，开展了土体加固试验研究。试验结果表明，生物酶对海洋土的加固效果最好，强度增加最高可达20%，而生物酶对完全风化花岗岩的加固效果则不太理想，抗剪强度指标只有少许改变。此外，海洋土和完全风化凝灰岩的压缩性因为生物酶的作用反而有所增强。最后，从微观上分析了生物酶固土作用的本质，指出固土效果主要缘自于生物酶分子与土中的黏土矿物分子发生相互作用产生的胶结作用。

英文摘要：

Conventional soil stabilization methods usually involve the addition of some agents or chemicals into soils to generate acomposite soil mass with high strength. However, the application of these soil stabilization methods, in general, requires a very longcuring time; and it is particularly not economical. By focusing on three typical local soils in Hong Kong, namely, marine clay,completely decomposed granite （CDG）, and completely decomposed tuff （CDT）, an experimental study of soil improvement ispresented, with the use of an innovative and practical bio-enzyme-based soil stabilization technology. As suggested by theexperimental results, the stabilization effect ofbio-enzyme on marine clay is the best, and unconfined compressive strength of marineclay is able to increase by as high as 20%; while the improvement effect on CDG soils seems not to be quite good since shearstrength indices have merely slightly changed after bio-enzyme treatment. It is to be especially noted that the compressibility ofmarine clay and CDT is improved after treatment, instead of being reduced. Furthermore, the fundamental mechanisms of thebio-enzyme-based soil stabilization are clarified from a microscopic perspective. It is pointed out that the stabilization effect mainlyresults from the bonding effect generated by the interaction between clay mineral molecules in soils and bio-enzyme molecules.