摘要
天津港作为我国的重要港口 ,近年来的发展突飞猛进。从陆上真空预压技术的提出至今 ,天津港在建设中充分应用这项技术并取得了良好的经济效益和社会效益。随着港口建设向深水区的发展 ,新型的水下软土地基加固技术的研究和应用被提到议事日程中来 ,进行水下真空预压的关键之一是射流泵的选取及其在水下工作机制的研究。为此进行了多次水下真空预压的模型试验 ,试验结果表明 ,水下真空预压中真空获得设备的工作机制与陆上真空预压存在明显区别 ,如随着设备入水深度的增加 ,真空获得设备内的水流量和流速不断增加而获得的真空度不断减小。为了合理地解释这些现象 ,深入了解水下真空预压技术的加固机理 ,文中结合流体力学与水力学的相关知识 ,展开了相应的理论推导 ,为这一现象推得了合理的理论解答 。
Being one of the important ports in China,Tianjin Port has made rapid progress in its development.Since the emergence of the vacuum preloading technique to improve soft soils on land,Tianjin Port has made full use of the technique in its construction works and has gained remarkable economic benefits and social benefits.With more ports being built in the deep waters,the study and application of a new type of technique to improve underwater soft soils have been put on the work agenda.One of the key issues in the underwater vacuum preloading technique is to select the adequate jet pumps and to study the mechanism of the jet pumps working in the water.For this purpose,quite a number of model tests have been made on underwater vacuum preloading.The results of these tests have shown that the working mechanism of the vacuumization equipment in underwater vacuum preloading was remarkably different from that in landbased vacuum preloading.For instance,with the increase of the submerged depth of the vacuumization equipment,the water volume and velocity in the vacuumization equipment were continuously increased,but the vacuum obtained was continuously reduced.To rationally interpret these issues,it is necessary to understand in a deep going way the mechanism of the underwater vacuum preloading technique in improving soft soils.Theoretical derivations are made in this paper in combination with the knowledge in fluid mechanics and hydraulics to obtain rationally theoretical solutions to these issues.The maximum water depth at which underwater vacuum preloading can take place is estimated according to the working performance of jet pumps in various water depths.
出处
《中国港湾建设》
北大核心
2003年第5期29-35,共7页
China Harbour Engineering
关键词
水下真空预压
射流泵
真空度
流速
流量
水深
underwater vacuum preloading
jet pump
vacuum
flow velocity
flow volume
water depth
