Research On The High-Accuracy Deformation Monitoring In Narrow Space

The subway 4A bid section of Shenzhen is of double-deck tunnel structure, designed to pass through the GuangShen quasi-high-speed railway, and needs to have an underpinning of the existing GuangShen railway bridge under construction. The underpinning area lies in the most flourish shopping center in the east of Shenzhen. During construction, various of tower shelves, scaffolds and supporting systems are jammed together, The activity room for monitoring works is very limited. It is the typical narrow space measurement.This thesis considers the situations of deformation monitoring in the project, also called "measurement in narrow space (MNS) " is proposed, and the methodology and practical problems related to the measurement in narrow space are studied. Through comparing and analyzing different kinds of methods of measurement in narrow space, The author proposes mainly utilizing highly automatic accurate digital level gauge and the total station which can transit automatically. Combining the special means of measurement, such as the combination of the high-accuracy relative measurement and the special measuring instrument offered on small yardstick, the author can solve the problem of measurement in narrow space in the underpinning of GuangSheng railway bridge.The thesis discusses the following content especially: (1)Utilize the automatic liquid static pressure level measuring system, cooperate with the level measurement of accurate geometry, introduce leveling datum to the narrow room, realize the anisochronous measurement of the leveling and monitoring net definitely and solve the problem of vertical deformation monitoring in the narrow space.