• Geomechanics and Engineering
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• v.23 no.4
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• pp.351-364
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• 2020

This paper numerically investigates the effects of a dip-slip fault (a normal or a reverse fault) movement on a segmental tunnel which transversely crosses either of this kind of faults. After calibration of the numerical model with results from literature of centrifuge physical tests, a parametric study is conducted to evaluate the effects of various parameters such as the granular soil properties, the fault dip angle, the segments thickness, and their connections stiffnesses on the tunnel performance. The results are presented and discussed in terms of the ground surface and tunnel displacements along the longitudinal axis for each case of faulting. The gradient of displacements and deformations of the tunnel cross section are also analyzed. It is shown that when the fault dip angle becomes greater, the tunnel and ground surface displacements are smaller, in the case of reverse faulting. For this type of fault offset, increasing the tunnel buried depth causes tunnel displacements as well as ground surface settlements to enhance which should be considered in the design.

• Structural Engineering and Mechanics
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• v.84 no.5
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• pp.699-706
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• 2022

Settlement control techniques are critical for the safety of shield tunnel constructions, especially for facing complex situations. In this study, the shield tunnel structure from Huaita east road station to Heping Road station in Xuzhou metro No.3 line (China) is taken as engineering background, which has various complex problems of the upper-soft and lower-hard composite stratum conditions, twin curve shield tunnels, and underpass the foundation of the piled raft. The deformation characteristics of shield tunnelling passing through buildings are explored. Subsequently, comprehensive research methods of numerical simulation and field measurement are adopted to analyzing the effectiveness of settlement control by using the top grouting technique. The results show that the settlement of the buildings has obvious spatial characteristics, and the hysteresis effect can be obviously observed in soil deformation caused by shield construction. Meanwhile, the two shield constructions can cause repeated disturbances, reducing the soil deformation's hysteresis effect. Moreover, the shield tunnel's differential settlement is too large when a single line passes through, and the shield construction of the outer curve can cause more significant disturbance in the tunnel than the inside curve. Notably, the proposed process control parameters and secondary topgrouting method can effectively control the deformation of the shield tunnel, especially for the long-term deformation.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.576-582
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• 2013

Typical highway infrastructure systems include roadway pavement, drainage systems, tunneling, and other hardware components such as guardrails, traffic signs, and lighting. Tunnels in a highway system have provided significant advantages to overcoming various natural challenges including crossing underneath bodies of water or through mountainous areas. While only a few tunnel failure cases have been reported, the failure rate is likely to increase as these assets age and because agencies have not emphasized tunneling asset management. A tunnel system undergoes a deterioration life cycle pattern that is similar to other infrastructure systems. There are very few agencies in the United States implementing comprehensive tunnel asset management programs. While current tunnel asset management programs focus on inspection, maintenance, and operation safety, there is an increasing need for the development of a comprehensive life cycle tunnel asset management program. This paper describes a conceptual framework for a comprehensive tunnel asset management program. The framework consists of three basic phases including a strategic plan, a tactical plan, and an operational plan to provide better information to the decision makers. The strategic plan is a basic long term approach of tunnel asset management. The tactical plan determines specific objectives and the operational plan actually applies asset management objectives in practice. The information includes operational condition, structural condition, efficiency of the system, emergency response, and life cycle cost analysis for tunnel capital improvement project planning.