击实对固化淤泥物理力学性质的影响

Effect of compaction on physical and mechanical properties of solidified dredged materials

淤泥固化技术中国进行工程应用时经常遇到需要碾压施工的问题,碾压后固化淤泥的力学性质是亟需试验明确的问题。研究了击实对不同水泥添加量和不同养护龄期下固化淤泥的密度、干密度、CBR和无侧限抗压强度的影响规律。结果表明,击实过程中存在有效击实次数,超过此次数后不能使土体进一步密实,击实土能达到的密度、干密度基本与固化土的相等;击实土的CBR强度可以从固化土的CBR得到,且约为固化土的1/10,固化土的CBR性质能够满足作为路堤填土的要求,而击实土则不能;固化土的抗压强度越大,击实土的抗压强度也越高,但是击实土相对于固化土的强度损失也就越大,击实土的无侧限抗压强度为固化土的1/3～1/2。因此,应根据实际淤泥固化工程的特点,合理选择水泥、石灰或复合型固化材料,这方面研究还有待更深入地开展。

The compaction technology has been generally employed in solidification of dredged materials in China. The mechnical behavior of the compacted solidified dredged materials is urgently needed to be cleared. The dry density, California bearing ratio （CBR） and unconfined compressive strength （UCS） of solidified dredged materials under proctor compaction tests are examined. The test results show that there exists an effective compaction number. The compaction becomes invalid when it exceeds the number, and the density and the dry density of compacted soil are basically equal to those of solidified soil. The CBR of compacted soil can be calculated by that of solidified soil, and is about one tenth of solidified soil. The CBR of solidified soil is easy to meet the standard requirements of embankment whereas the compacted soil can not. The higher the UCS of solidified soil, the larger the UCS of compacted soil. However, the strength loss is also greater, i. e. the UCS of compacted soil is about one third to half of that of solidified soil. Accordingly, in the practical solidification of dredged materials, strong bonding cement, weak bonding quicklime or composite modified materials should be reasonably chosen.