• Journal of the Korea institute for structural maintenance and inspection
• /
• v.4 no.2
• /
• pp.175-184
• /
• 2000

The maintenance of tunnels is often neglected since tunnels has tendency to become stable with time. The determination of safety of tunnels is a complicated problem. So the role of experienced engineer in the maintenance is very important and development of an expert system which can perform as these engineers has been needed. In this study, an expert system which can determine the safety of tunnels is developed. The developed knowledge base contains the maintenance procedure which is used in KlSTEC(Korea Infrastructure Safety & Technology Corporation). Field test, laboratory test and nondestructive test methods are considered in this knowledge base. Criteria for each item and integrated diagnosis criteria are implemented in the expert system based on literatures and reports. The expert system includes basic inspection. detail inspection and precision inspection. For precision inspection. it has the capacity to exchange the result from numerical analysis by a commercial program FLAC. To verify the expert system. the proposed procedure was compared with an existing tunnel diagnosis report.

• Journal of Korean Society of Disaster and Security
• /
• v.7 no.2
• /
• pp.9-16
• /
• 2014

Though the maintenance monitoring of structurally weak parts of the tunnel structure in public service must be judged in connection with the monitoring during the construction period for analysis of the behavior of the ground and surrounding structures following the tunnel excavation for the effective management, the monitoring during the construction period and the maintenance monitoring are implemented separately on the basis of the periods of construction and maintenance, so the connectivity and systematic management of the related data are mostly inadequate. The improvement direction is suggested in this thesis, by analyzing the problems of tunnel monitoring in the domestic design criteria. And, it is anticipated that from now on the use of hi-tech sensors and wireless communications technology will proceed vigorously in the maintenance, so considering these situations, the development and application of the maintenance monitoring system and the revision of the domestic design criteria and specification are needed in the future.

• Geomechanics and Engineering
• /
• v.29 no.3
• /
• pp.349-357
• /
• 2022

Abnormal climate events are occurring frequently around the world. In particular, cold waves and heavy snow lead to damage and deterioration of facilities, which can cause loss of life or property damage, such as shortening the lifespan of facilities. Therefore, it is very important to prepare an appropriate maintenance system and to establish a strategy to cope with abnormal weather conditions. In this study, laboratory freezing experiments were performed to analyze the freeze-thaw characteristics affecting the tunnel concrete lining, and heat flow analysis was carried out based on the test results. Based on these experimental and theoretical analysis results, quantitative freeze-thaw evaluation criteria for tunnel concrete linings were proposed.

• Journal of the Korea Concrete Institute
• /
• v.14 no.3
• /
• pp.341-348
• /
• 2002

The purpose of maintenance monitoring is to offer the objective and continuous data in order to be lasting security affirmation and best fitted maintenance of tunnel structure. Though recently the examples of maintenance monitoring which Is applied to tunnel are rapidly increasing, long-term measured monitoring actual results and rationally analysis method researches are wholly lacking. In this study, it is analyzed that the relationship of stress and reinforcement stress of concrete lining, i.e., last support materials of tunnel through regression analysis based on the monitoring result of the subway tunnel, which was accomplished the monitoring for long period, passing the weathering. Also, through the analysis of the stress and the safety of concrete lining, it is estimated that the frequency of maintenance monitoring and the in-situ application of the criteria value of management.

• Journal of the Society of Disaster Information
• /
• v.16 no.1
• /
• pp.10-20
• /
• 2020

Purpose: Analyze the results of on-site inspection of the tunnel structure maintenance management monitoring and suggest improvement plans. Method: We investigate and analyze the problems of various items on maintenance monitoring of tunnel structure of 14 subway lines of Seoul subway in downtown area. Result: The maintenance monitoring items, measurement quantity and installation location are classified into open tunnel and excavation tunnel and improvement plans are suggested respectively. Various durability criteria of the measuring instruments were examined, and durability confirmation method suggested improvement measures such as approval, inspection, inspection and testing, calibration of monitoring sensors. Conclusion: Applying the improvement measures of the tunnel structure maintenance monitoring to the construction site will increase the efficiency of the maintenance monitoring and contribute to the development of construction monitoring technology.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.1
• /
• pp.83-93
• /
• 2017

Recently, the development of multi-purpose tunnel that has functions of roads and waterways has been attention for efficient utilization of underground space. However, there is no study on the multi-functional tunnels behavior for the convert of iterative function and change of water pressure. In this study, the vulnerable section was analyzed due to repeated functional change. A basic review was implemented for the operation of the multi-purpose double-deck tunnel. Also, the vulnerable section for convert of iterative function of multi-functional tunnel has been analyzed by simulation. Management of multi-functional tunnel should considered in various analyzed and some problems. The criteria for management of multi-functional tunnels is proposed.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.73-78
• /
• 2008

There has been need for safety monitoring systems for the social infrastructures. These infrastructures are subject to degradation over time, reduced functionality, and loss of functionality as a result of factors such as a wide variety of installation environments, natural disasters, and nearby work. Therefore, it is necessary to perform appropriate inspections, repairs, and renovations to ensure safe and efficient maintenance and operation. This paper introduces the example of the development of the safety monitoring system for operating railway tunnel. Tunnel profile measuring system using laser beam, crack gauges, accelerometer and a pluviometer were implemented to monitor the safety of a deteriorated tunnel. The measured data were transferred through wireless network and analyzed in real time. The safety criteria for tunnel stabilities and train operations are also discussed.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.6
• /
• pp.25-34
• /
• 2017

Since the 30-year-old facility is expected to surge from 10.5% to 23.9% in 10 years, the new evaluation system is needed to establish efficient maintenance system for securing the safety and extending the life span of existing facilities. In this study, Delphi and AHP(Analytic Hierarchy Process) was conducted to provide a systematic new evaluation system for the NATM tunnel, which is the most frequently constructed structure of the existing tunnel. Since the existing assessment systems are limited in scope of evlauatuon criteria, the survey was conducted in conjunction with closed questionnaires on existing items and open questionnaires for eliciting new items. In results, suitable evaluation factors were derived for the NATM tunnel through the validation of the survey results. Also after calculating weighted value of the derived assessment item using AHP technique, a new evaluation system is proposed to meet the characteristics of the NATM tunnel, so that they can be used as reference materials for revising and supplementing detatiled guidelines in the future.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.979-987
• /
• 2011

The Ballast Track has been widely applied in traditionally due to low initial cost and abundant elastic property. But the disadvantages of Ballast track are; labor-intensive and costly maintenance, weak in high-speed and heavy axial load, in additionally need wide cross section of tunnel and massive substructure in viaduct. Therefore, recent applications tend to more and more towards slab track such as Gyeungbu high speed rail and existing line. The slab track increased the stability, resistance and durability of track, and save maintenance cost compare to the Ballast Track. But the slab track have weakness of track elongation by sub-ballast differential settlement and that threat safety of train operation. Therefor the slab track need to prevent cracks in concrete ballast for insure the durability of slab track. In this paper, review main items and its expected effects of the slab track maintenance standards that control sub-ballast settlement and concrete ballast cracks.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.24 no.6
• /
• pp.715-724
• /
• 2022

With the enforcement of the infrastructure management act, the importance of utility tunnels that jointly accommodate life-lines such as electricity, communication, water supply, and heating facilities has increased. The currently applied utility tunnel maintenance system is managed in an accident-preventive safety-based evaluation method. However, this evaluation method has limitations in effective maintenance. In this study, performance evaluation items were derived through the Delphi method to suggest a criterion for quantitatively evaluating the performance of utility tunnels, and the weights for each item were calculated through the Analytic Hierarchy Process (AHP) method. In the future, it is judged that a more reasonable performance evaluation standard of utility tunnel can be prepared if modifications and supplements are made through field application.