Seong-Won Lee

Korea Institute of Civil Engineering and Building Technology | KICT · Geotechnical Engineering Research Institute

The new Austrian tunnelling method (NATM) and tunnel boring machine (TBM) are methods for excavating underground spaces. The NATM construction method has noise and vibration problems, and excavation using TBM has the disadvantage of high initial cost and is limited by ground conditions. A parallel TBM and NATM construction method has been developed...

To ensure the safety of a concrete structure, periodic and accurate inspection for damage is necessary. However, there is a high risk of inaccurate diagnosis of the structure condition because the manual inspection method is dependent on operator experience and subjective judgment. Additionally, in future society, it may become increasingly difficu...

The functional performance of concrete structures degrades over time as a result of continuous loads, stress fatigue, and external environmental changes. Thus, periodic diagnoses and inspections are essential because such conditions can eventually lead to disaster. Hence, the detection of cracks in concrete is a key component of structural manageme...

The development of underground spaces in urban centers has attracted significant research attention. Typical excavation methods for underground spaces in urban areas include the New Austrian tunneling method (NATM) and the tunnel boring machine (TBM). The NATM is superior in terms of ease of construction and economic efficiency; however, vibration...

Road maintenance technology is required to maintain favorable driving conditions and prevent accidents. In particular, a sensor technology is required for detecting road damage. In this study, we developed a new sensor technology that can detect road damage using a deep learning-based image processing algorithm. The proposed technology includes a s...

Instrumentation during tunnel construction can be used as reference data to identify anomalies, find the causes, and develop countermeasures through data trend analysis in terms of the construction, maintenance, and management of tunnels. Therefore, obtaining reliable and accurate data is very important to prevent large accidents and minimize damag...

In this paper, we propose a novel neural network structure and training and prediction methods. We propose a novel deep neural network algorithm to detect road surface damage conditions for establishing a safe road environment. We secure 1300 training and 400 testing images to train the neural network; the images contain multiple types of road dist...

Vital underground structures such as sewers, power transmission lines, subways, and underpasses are potentially vulnerable to adverse effects from aboveground construction. In this study, the influence of pile installation on nearby existing tunnels was investigated. Both a laboratory model test and finite-element numerical analysis were conducted....

Recent studies have increasingly investigated construction methods for tunnel excavation because of growing underground space development. Although the New Austrian tunneling method (NATM)—a representative tunnel excavation method—can be applied to various ground conditions, as well as having good constructability and economic feasibility, it suffe...

In this study, the cyclic responses of an offshore wind turbine with a tripod foundation installed on an actual site were evaluated in a centrifuge. To understand the behavior of the turbine at the site, the site soil conditions, environmental loads, and real offshore wind turbine structure installed at the actual site were modeled by considering t...

The damage investigation and inspection methods for infrastructures performed in small-scale (type III) facilities usually involve a visual examination by an inspector using surveying tools (e.g., cracking, crack microscope, etc.) in the field. These methods can interfere with the subjectivity of the inspector, which may reduce the objectivity and...

Typically, the operational lifetime of underground concrete structures is several decades. At present, many such structures are approaching their original life expectancy. In this stage, the essential functionality of the structures may be considerably degraded, leading to various safety hazards such as collapse roof and tunnel flooding. In general...

The road network system of major domestic urban areas such as city of Seoul was rapidly developed and regionally expanded. In addition, many kinds of life-lines such as electrical cables, telephone cables, water&sewerage lines, heat&cold conduits and gas lines were needed in order for urban residents to live comfortably. Therefore, most of the life...

In subsea tunnelling, prediction of the fractured zone (or water bearing zone) ahead of tunnel face saturated by seawater with high water pressure has been a key factor for safe construction. This study verified the feasibility of utilizing induced polarization (IP) survey at tunnel face for predicting the ground condition ahead of the subsea tunne...

This study investigates the influence of the wavelength of a tooth-shaped surface asperity (λ) on the characteristics of the fracture wavelength (λ f ) and the plane interface shear strength (τ f ). A total of 53 plane interface direct shear tests were conducted by changing the slope angle of surface asperity, wavelength of surface asperity, and no...

Estimation of loads acting on NATM tunnel concrete lining is one of the major issues in tunnel design. Generally, the tunnel loads are estimated by empirical methods, but those are likely to be subjective and sometimes too excessive. Ground-Lining Interaction(G.L.I) model has been developed on the concept that the secondary lining supports the grou...

The rock mass is usually damaged/fractured during the blasting. Quantitative investigation of the damaged depth is needed for stability of underground structures such as tunnels. This study deals with the blast-induced damage identification of rock mass using the surface wave method based on wavelet transformation. A series of site test were conduc...

Tunnel and underground utility projects have gradually increased in Korea through 21st century. The use of TBMs (Tunnel Boring Machine) is expected to be increased due to the high demand for sustainable and eco-friendly tunnel construction in Korea. This paper discusses the performance and development of TBMs in Korea. The advance rates of TBM in t...

Currently, advanced nations have been expanding underground traffic facilities in an effort to ease the traffic congestion as well as secure the green space on the ground in metropolitan area and a various projects aimed at achieving such a purpose have been also implemented in Seoul metropolitan area in Korea, where however not many deep road tunn...

Due to the limitation of construction efficiency and structural safety, the application of the high covering and wide width tunnels was limited prior to the introduction of precast rut and cover tunnels. Therefore, a cut and cover tunnel structure with rib reinforcement is proposed to mechanically improve the safety on condition of high covering an...

Due to the limitation of construction efficiency and structural safety, the application of the high covering and wide width tunnels was limited prior to the introduction of precast cut and cover tunnels. Therefore, a cut and cover tunnel structure with rib reinforcement is proposed to mechanically improve the safety on condition of high covering an...

The behavior of a jointed rock is different from that of an intact rock, and the characteristics of elastic wave propagation in a jointed rock are different from those of an intact rock. In this study, a rock resonant column testing device is designed to measure the longitudinal and flexural wave velocities of jointed rocks under different states o...

Although the round length for tunnel excavation has a major technical and economical impact in conventional tunnelling, there is no coherent procedure available for its determination. In this study, the influence of round length on the behaviour modes of weak rock tunnel was investigated by numerical analyses. Quantitative estimation of the behavio...

Rockbursts are mainly caused by a sudden release of the stored strain energy in the rock mass. They have been the major hazard in deep hard rock mines but rarely occur in tunnels. Due to the short history and limited information on rockbursts, the topic has rarely been studied in Korea. Some cases of rockbursts, however, have been reported during c...

The detection of structural damage of concrete is one of the most important issues associated with improving maintenance procedures and increasing the service life of structures including tunnels. To investigate the safety and stability of the tunnel concrete lining, numerous studies have been conducted over the years and several methods have been...

This paper presents a new strategy for determining an optimum position of monitoring point and criteria with which judgment is made if the settlement values at the point are critical or not for a significant structure adjacent to tunnel construction. The position and criteria are differently given to each structure by considering its geometry and e...