The frequent occurrence of earthquakes worldwide has rendered highway slope protection projects highly vulnerable to damage from seismic events and their secondary disasters. This severely hampers the smooth implementation of post-disaster rescue and recovery efforts. To address this challenge, this study proposes a comprehensive method for assessing seismic losses in slope protection projects, incorporating factors such as topography and elevation to enhance its universality. The method categorizes seismic losses into two main components: damage to protection structures and costs associated with landslide and rockfall clearance and transportation. This study estimates the cost range for common protection structures and clearance methods under general conditions based on widely recognized quota data in China. It establishes criteria for classifying the damage states of protection structures and provides loss ratio values based on real-world seismic examples and expert experience, constructing a model for assessing damage losses. Additionally, by summarizing the geometric characteristics of soil and rock accumulations on road surfaces, a method for estimating landslide volumes is proposed, considering the dynamic impact of slope gradients on clearance and transportation volumes, and a corresponding cost assessment model for clearance and transportation is developed. The feasibility and reliability of the proposed method are verified through two case studies. The results demonstrate that the method is easy to implement and provides a scientific basis for improving relevant standards and practices. It also offers an efficient and scientific tool for loss assessment to industry practitioners.

Buried water pipelines, as crucial urban infrastructure, play an essential role. However, the damage to the pipeline structure has emerged as a severe public safety hazard. Monitoring the state of the pipeline structure holds great significance for the normal operation of water pipelines. In this paper, a damage monitoring method for buried pipelines based on distributed acoustic sensing technology is proposed. Through a series of field experiments conducted on a pipeline, the feasibility of utilizing the attached fiber-optic cable to acquire vibration information has been demonstrated. The recorded vibration signals can indicate various damage statuses during the pipeline damage process, including rock/soil fall, pipeline seepage, and pipe wall failure. The results suggest that the fiber-optic cable accompanying the pipelines can be exploited as sensing resources to monitor damage risks to the pipelines, which presents advantages in the damage identification and location of buried pipelines. This research provides a valuable reference for the application of distributed acoustic sensing technology in the damage monitoring of urban buried water pipelines.

This paper proposes a performance-based damage assessment procedure for reinforced concrete (RC) box tunnels subjected to earthquakes, employing a pseudostatic approach and a ductility-based damage index that incorporates the relative stiffness between the structure and surround soil, widely denoted as flexibility ratio (F). Distributed plasticity frame elements and discretized spring elements were used to model tunnel structures (slabs, walls, and columns) and the reactions of surrounding soil, respectively. Two damage-state descriptors were investigated: one based on the number of yielding in the tunnel members and another on the material state. Results show that the number-of-yielding based descriptor captures global structural capacity only for specific F ranges, while drift ratio lacks consistency as a damage index across all F ranges. In contrast, the material-state descriptor and damage indexes based on curvature ductility provide effective capacity estimation and are independent of F. Therefore, combining both descriptors is recommended for seismic performance evaluation of RC box tunnels. Additionally, higher F leads to brittle failure due to better load distribution and increased yielding before the strength degradation, while lower F results in concentrated damage with less yielding. These findings highlight the necessity of seismic design considering flexibility ratio for earthquake-resistant tunnels.

Seismic damage indices (SDIs) quantify damages in civil structures at local or global level due to seismic activities with the help of various demand and capacity parameters. Conventionally, SDI estimation requires complex and computationally demanding nonlinear time-history analysis (NTA) to find the values of the demand parameters. Nowadays, buildings are equipped with sensors to monitor their responses during seismic activity. Therefore, a novel method utilizing such recorded floor-displacement data of reinforced concrete (RC) plane frames along with local and global capacity-based parameters to predict combined global damage index (GDI) is presented here. Two different GDI formulas, depending on the type of capacity parameters, are developed following the proposed method. Multilinear regression analysis is performed to develop the proposed formulas such that they can predict the GDIPA\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$GDI_{\textrm{PA}}$$\end{document} calculated from hysteresis energy-based weighted average of modified Park and Ang local damage indices. The application of the new method does not need dynamic responses of RC frames obtained from NTA. However, for establishing the new method in the present study, the output of NTAs for different RC frames due to several design spectrum-compatible ground motions are used for training and validation. Also, the explicit expressions for the regression coefficients are provided in terms of some structural properties (e.g., fundamental period, total height) and local soil type for wider applicability. It has been found that the estimated GDI values using the proposed method can satisfactorily represent global damage states based on the limiting values of GDIPA\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$GDI_{\textrm{PA}}$$\end{document} for the RC frames.

A novel method is proposed for predicting the combined global damage index through newly developed formulae utilizing recorded floor-displacement data, local and global capacity-based parameters for 3D RC buildings. Multilinear regression analysis is performed to develop the new formulae for predicting the global damage index obtained from modified Park and Ang-type 3D local damage indices. Further, explicit expressions for the global damage coefficients of the new formulae are developed as a function of structural properties and soil type for wider applicability of the formulae. The computed global damage indices are found to represent the damage states of RC buildings satisfactorily.