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• The damage cause of ground surface and tunnel lining during tunneling is studied. • The tunnel damages during tunneling in silty clay can be reasonably simulated. • The field monitored softening soil body has much influence on tunnel damages. This paper presents a case study of investigating the cause of tunnel damages during tunneling in silty clay, in which the damages are existed in both ground surface and tunnel lining. The study is implemented by field investigation and numerical back analysis to determine the cause of tunnel damages, in which the field observed funnel-shaped surface subsidence of ground and surrounding soil moving to the tunnel are considered as softening soil body from ground surface until surrounding rocks in the numerical model, and the material parameters of the field monitored softening soil body are respectively taken as 0.8 times and 0.6 times of the original ones. This work confirms that the field observed tunnel damages during tunneling in silty clay can be numerically simulated, which is significantly influenced by the field monitored softening soil body from ground surface until surrounding rocks. [ABSTRACT FROM AUTHOR]

This paper presents a case study of landslide during tunneling period in hilly topography, and a practical treating countermeasure is also proposed in the study. The field investigation and numerical analysis demonstrate that tunneling in hilly topography with sloping stratification has risk of landslide while heavy rainfall permeates into ground, and a treating countermeasure of anti-slide piles combined with in-layer compacted backfilling is adopted in the practical implementation. Moreover, the implemented treating work demonstrates that the employed countermeasure is capable of treating landslide during tunneling with heavy rain water permeating into ground, which can provide the design basis for similar treating work. • A case of landslide during tunneling is presented. • The landslide is caused by tunneling in hilly topography with heavy rainfall. • The primary cause of landslide during tunneling can be numerically clarified. [ABSTRACT FROM AUTHOR]

Abstract A case of damaging behavior in the concrete lining of an operational railway tunnel is studied and presented in this paper. The study focuses on the influence of tunnel structure damaging due to field observed construction deficiency of cavities around surrounding rocks, which is evaluated by means of field observation and numerical analysis. This work demonstrates that the construction deficiency of cavities around surrounding rocks plays an important role in the stability of tunnel structure, which can vary the stress state distribution of tunnel structure even with damaging behavior. Moreover, the implemented numerical analysis also demonstrates that the damaging behavior of tunnel structure induced by the field investigated cavities can be numerically simulated with taking account of the aforementioned cavities in the numerical model, which provides the design basis for appropriately strengthening the damaged tunnel structure. Highlights • A case study of damaging behavior in an operational tunnel structure is presented. • The assumed lightweight elastic material can be adopted for modeling the cavity. • Construction deficiency of cavity has much influence for tunnel structure stability. [ABSTRACT FROM AUTHOR]

This paper presents a case study of investigating damages in existing building adjacent to foundation pit in construction, in which the settlement influence of adjacent building induced by constructing foundation pit is demonstrated by means of field observation, numerical analysis and experimental investigation. This study focuses on the principal cause inducing these damages in the existing building. This work demonstrates that the stratum settlement of the existing building during excavating foundation pit are significantly influenced by not only construction task of excavating soils but also that of dewatering soil mass in constructing foundation pit, since the principal constitution of fine sand and medium sand in the sludge can be easily run off with stratum loss during the dewatering task, and the hydraulic connection between the inside and outside of the foundation pit thus can't cut off using underground continuous wall, which can probably produce structural damage of soil mass with stratum settlement. [ABSTRACT FROM AUTHOR]