潮差带区域水下真空预压技术研究

发布时间：2018-10-13 13:21

【摘要】：随着我国经济实力的增强和沿海岸线的开发，有大量的工程需要建设在潮差带浅海区域。受区域环境和地质条件的影响，我国的沿海地区大都是新近沉积的淤泥质粘土或淤泥，为港口工程建设带来了极大的困难。目前对水下软土地基多采用深层水泥搅拌法（CDM法）或砂桩法（SCP法）进行处理，费用高昂且需要一些大型的专用施工设备。而真空预压法是目前陆上软土地基加固的首选方法，预压荷载可一次快速施加地基不会失稳，同时也不需要堆载材料、避免了堆载材料的开采和运输，因此，研究真空预压技术在水下软基处理工程中的应用是非常有意义的。由于受到施工技术的限制，真空预压法的所有工序都在水下施工尚有一定的困难。做为水下真空预压技术的过渡阶段，充分利用潮差带区域涨落潮的环境特点，对真空预压工艺进行相应的改进，在潮差带区域成功进行了4项水下真空预压处理工程，形成了成套地基处理技术，取得了良好的效果。本课题研究的主要成果如下：（1）、潮差带区域水下真空预压技术同陆上真空联合堆载预压相比，其加固机理同非常相似，只是联合堆载荷载是一个变动水荷载。潮差带区域水下真空预压设计时，预压荷载可取膜下真空荷载与膜上平均水压荷载之和。膜上平均水压荷载可根据施工期间的潮水位和地面标高进行分析计算。（2）、通过对潮差带区域进行的4项水下真空预压处理工程进行总结，，对铺设砂垫层技术、打设排水板技术、埋设密封膜技术等进行了相应的改进，形成了成套施工技术。（3）、针对水下监测的特点，开发了现场监测数据自动记录和传输技术，实现了地基监测数据的自动测量、自动采集、自动存储和自动传输功能。研究结果表明，水下真空预压技术可以在潮差带区域大量的工程建设中应用，起到节约工程造价和缩短工程工期的目的，其应用前景非常广阔。
[Abstract]:With the strengthening of economic strength and the development of coastline, a large number of projects need to be built in shallow area of tidal zone. Under the influence of regional environment and geological conditions, the coastal areas of China are mostly recently deposited silt clay or silt, which brings great difficulties to the construction of port engineering. At present, deep cement mixing method (CDM) or sand pile method (SCP method) are used to treat the underwater soft soil foundation, which is expensive and needs some large special construction equipment. The vacuum preloading method is the first choice for the reinforcement of the soft ground on land at present. The preloading load can quickly impose the foundation without instability, and at the same time, it does not need the surcharge material, thus avoiding the mining and transportation of the surcharge material. It is very meaningful to study the application of vacuum preloading technology in underwater soft foundation treatment engineering. Due to the limitation of construction technology, it is difficult to construct all the processes of vacuum preloading under water. As the transition stage of underwater vacuum preloading technology, the vacuum preloading process is improved by making full use of the environmental characteristics of the fluctuating tide in the tidal zone. Four underwater vacuum preloading projects have been successfully carried out in the tidal zone. A complete set of foundation treatment technology has been formed, and good results have been obtained. The main results of this paper are as follows: (1) compared with overland vacuum combined surcharge preloading, the consolidation mechanism of underwater vacuum preloading in tidal zone is very similar, except that the combined surcharge is a variable water load. In the design of underwater vacuum preloading in tidal zone, the sum of the vacuum load under the film and the average hydraulic load on the film is desirable. The average water pressure load on the film can be analyzed and calculated according to the tide level and the surface elevation during construction. (2) by summarizing the four underwater vacuum preloading projects in the tidal zone, the technology of laying sand cushion is discussed. The technology of drainage board and sealing film are improved accordingly, and a complete set of construction technology is formed. (3) in view of the characteristics of underwater monitoring, the automatic recording and transmission technology of field monitoring data is developed. The functions of automatic measurement, automatic acquisition, automatic storage and automatic transmission of ground monitoring data are realized. The research results show that the underwater vacuum preloading technology can be used in a large number of engineering construction in the tidal zone, which can save the project cost and shorten the construction period, and its application prospect is very broad.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：U655.54;TU472.33

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