Railway traffic becomes an important rapid transportation system within metropolitan area. Taipei metro-network expands rapidly and increases system loading after more than 10 years of operations. It is very difficult to finish intensive tunnel inspection and maintenance works within daily limited of time. So, it needs to adopt latest techniques such as tunnel lining scanning equipment to execute inspection and offer the information to proceed the following periodically maintenance work which can extend the tunnel life cycle. Through reviewing the execution of tunnel inspection and propose the problems of tunnel , inspection technique, tunnel abnormal patterns, maintenance principle, and segment leakage repaired technique to develop the improvement as required.
Case Study on the Application of Geotechnical Instruments for Safety Control in the Construction Works of Taipei MRT Tunnels Underpass Beneath High Speed Rail Part 1: Construction Works and Monitoring Results before Shafts Excavation)
This paper describes the monitoring results and safety control during construction works of Taipei MRT close proximity to Taiwan High Speed Rail(THSR).This paper which consists of two parts, Part 1 as reported herein the close proximity constructions procedure and planning of geotechnical instrumentation to Taiwan High Speed Rail(THSR) ,the monitoring results and safety control during the diaphragm walls, jet grout slab grouting, and bottom seal grout in the working shafts, lowering of ground water in order to check the effectiveness of bottom seal, high pressure grout with triple tube technique conducted beside the diaphragm walls of working shafts where the walls to be knocked out.
Case Study on the Application of Geotechnical Instruments for Safety Control in the Construction Works of Taipei MRT Tunnels Underpass Beneath High Speed Rail Part 2: Construction Works and Monitoring Results after Shafts Excavation
This paper is the Part 2 of the previous paper describes the monitoring results and safety control during construction works of Taipei MRT close proximity to Taiwan High Speed Rail(THSR), including brace excavation, horizontal chemical grout conducted behind the THSR diaphragm walls where the walls also to be knocked out , horizontal sleeve grout with double packer method to strengthening and reduced permeability of soil beneath the THSR and Taiwan Railway Administration (TRA),both up track and down track of CG290 bored tunnels of Taipei MRT underpass beneath THSR and TRA ,and the remaining H piles from SMW to be removed from the front side of shield machine. This project was commenced in April of 2009 and successfully completed in August of 2012, and the maximum deformation of THSR structures caused by Taipei MRT construction works was only about 40% of action value specified by THSR structures and track allowable deformation.
Taiwan is located in one of the seismic zones most frequently around the world. For reducing disasters in earthquake, except earthquake-resistant construction, how to meet an emergency during earthquake is another focus. Therefore, construct a real time seismic monitoring system to provide real time information in earthquake is the best way for disaster reducing. Due to all of the Taipei Metro lines and stations are constructed by different contractors, each seismic monitoring sub-system including instruments and real time data stream code will be different. Base on this situation, integrate all sub-systems which were built by different contractors is necessary. This article will introduce the seismic monitoring system of Shin-Lu Line. It’s the first time that Taipei Metro uses real time seismic monitoring system on underground structures. Whole system include seismic and static structure safety monitoring sub-system in 8 stations, transferring the data from each station to CCR, integration on CCR and data base. We also show the ground motion data and figures which were recorded by the sub-system of San-Chong station at June 10, 2012 earthquake for all who are interesting at this topic.
A serious landslide occurred at chainage 3k+100 (Keelung-Xizhi section) of National Freeway No. 3 on the afternoon of April 25, 2010, leading to several casualties and blockage of major traffic between Keelung and Taipei City. Facing such a critical and extensive incident, the authority, Taiwan Area National Freeway Bureau, MOTC, immediately launched a series of rescue and slope remediation actions. At the same time, an automatic monitoring system for the slopes was planned and established for the long term observation of the subsequent stability condition. This paper introduces the process of the system setup, including determination of management levels, calibration, and contingency measures. It is hoped to be as a reference for the similar projects.
Landslide monitoring sites are growing with the raising awareness of hazard prevention. Many landslide monitoring cases are still at initial stage thus cannot provide sufficient information for reference. Therefore the monitoring values for landslide management are adopted with Japan regulations. However, the values for Taiwan’s landslide management need to re-considerate with different geological conditions and manual monitoring system comparing with Japan’s automatic monitoring system.
More than 10 landslide monitoring sites are collected in this study. Displacement measurements such as slope indicator, ground extensometer, and in-hole extensometer that have direct relationship with landslide stability are selected to analysis comparing with landslide monitoring cases in other countries. The displacement monitoring results of these instruments are analyzed and proposed displacement values for management to prevent the misuse of monitoring values.
Water is one of the essential resources for human existence. Because of the geological characteristics of Taiwan, dams and reservoirs are the main facilities used to provide water of livelihood, industry and agriculture purposes in Taiwan. The safety of the dam or reservoir is closely related to its monitoring system via the analyses and interpolations of the monitoring data. In the past, most of the monitoring data were collected manually. Because of the help of the modern technology, many instruments can collect monitoring data automatically now. This article presents procedures and suggestions for the automatic monitoring system of the dam or reservoir. A case study on the monitoring system of Shihmen reservoir is also introduced in this article.
The variations of pore water pressure and displacement in ground are important parameters in many geotechnical engineering field monitoring. Combining multiple sensors with different functions into an array enables profile information to be obtained in a single borehole and enhance its effectiveness. Optical fiber Bragg Grating (FBG) has the advantages of being minute, durable, immune to lightning, electromagnetic interference and short circuit, and capable of connecting multiple FBG’s using a single optical fiber. The optical signal can be transmitted to tens of kilometers away without losing its quality. The authors at the optical fiber sensor laboratory of National Chiao Tung University have developed a series of FBG sensing techniques that include segmented deflectometer, inclinometer, piezometer, and extensometer. Integrating various types of FBG sensors and insert them into the borehole as an array, the authors were able to perform real-time pore water pressure, lateral displacement and subsidence profile monitoring. The paper describes principles of these FBG sensing techniques and cases of field deployment of FBG sensor arrays for slope stability, dike safety, and ground subsidence monitoring.