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Adaptation to climate change requires careful evaluation of infrastructure performance under future climatic extremes. This study demonstrates how a multidisciplinary approach integrating geotechnical engineering, hydrology, and climate science can be employed to quantify site-specific impacts of climate change on geotechnical infrastructure. Specifically, this paper quantifies the effects of changes in future streamflow on the performance of an earthen levee in Sacramento, California, considering multiple modes of failure. The streamflows for historical (1950–2000) and projected (2049–2099) scenarios with different recurrence intervals were derived from routed hydrological simulations driven by bias-corrected global climate models. The historical and future flood levels were then applied in a set of transient coupled finite-element seepage and limit equilibrium slope stability analyses to simulate the levee subjected to extreme streamflow. Variability in hydraulic and mechanical properties of soils was addressed using a Monte Carlo sampling method to evaluate and compare the probability of failure of the levee under different historical and future climate scenarios. Three individual modes (underseepage, uplift, and slope stability) along with lower and upper bounds for the combined mode of failure were examined. The results showed that incorporating future floods into levee failure analysis led to considerable reductions in the mean factor of safety and increases in the levee's probability of failure, suggesting that risk assessment based on historical records can significantly underestimate the levee's failure probability in a warming climate. Despite inherent uncertainties in future projections and substantial variability across climate models, evaluating infrastructure against projected extremes offers insights into their likely performance for the future. [ABSTRACT FROM AUTHOR]

This paper presents the results of a systematic well designed experimental investigation carried out to study the engineering properties of the soft Bangkok clay heated up to 90°C from room temperature (25°C). Details of modified oedometer and triaxial test apparatus that can handle temperatures up to 100°C are also presented. In the range of temperatures investigated, soft Bangkok clay exhibited temperature induced volume changes that depend mainly on the stress history, reduction in the conventional elastic zone, stiffening, and increased hydraulic permeability with increasing temperature as well as apparent overconsolidation state after subjecting the normally consolidated specimen to heating/cooling cycle. The results of this study provide additional data that can enhance the understanding of the thermohydromechanical behavior concepts of saturated clays. [ABSTRACT FROM AUTHOR]

An extreme rainstorm can cause thousands of landslides and kill hundreds of people. In the changing climate, fatal rainstorms become more frequent and intense. The current landslide emergency management evaluates hazard intensities but lacks key information on likely consequences. This study presents a novel prompt quantitative risk assessment method for rain-induced landslides. The proposed method automatically generates a one-page risk assessment report within minutes to support effective risk communication, resource allocation, and emergency response. The propagation of uncertainties is quantified in a scientific probabilistic framework. The proposed method is tested using 83 major rainstorms during 1995–2016 in Hong Kong. The method accurately predicts the number of affected buildings and the number of potential fatalities and identifies rainstorms that can trigger fatal landslides. The proposed method contributes to the advancement of landslide emergency management from hazard-informed to risk-informed, which will significantly enhance societal resilience and facilitate climate change adaptation. [ABSTRACT FROM AUTHOR]

Risk assessment for large engineered systems involving geotechnical uncertainties—such as dams, coastal works, industrial facilities, and offshore structures—has matured in recent decades. This capability is becoming an ever more pressing concern considering increasing natural hazards and the effects of climate change. This progress and the current state of practice are reviewed by considering four projects. An underlying theme is what we have learned about how geoprofessionals should think about uncertainty, judgment, and risk. The organizing key is Bayesian thinking, which is neither new nor unintuitive to most geoprofessionals. However, this way of thinking and analyzing data is powerful, even when dealing with the sparse data of geotechnical projects. The presentation builds on the past Terzaghi Lectures of Casagrande, Whitman, and Christian. It uses examples of infrastructure systems for which geotechnical considerations were important. Reliability concepts developed in this earlier practice provide a window into the processes of integrating site characterization data, judgment, engineering models, and predictions to achieve tolerable levels of risk. Along the way, arguments are made on the nature of uncertainty and on the benefits of processing data, judgment, and inferences through a consistent lens. [ABSTRACT FROM AUTHOR]

Rock instability and rockfalls are commonly preceded by the initiation and propagation of cracks. This process is accompanied by the release of microseismic energy, which can be detected by means of an appropriate monitoring system. Because an increase in rockfall events have been observed in the Matterhorn Peak area since 2003, in 2007 a microseismic monitoring system and a thermometric monitoring system were installed on the Italian side of the Matterhorn peak, close to the J. A. Carrel hut, as part of the Interreg IIIA Alcotra 'PERMAdataROC' project. The objective of the installation was to determine whether this instability increase was connected to climatic fluctuations. Detailed analysis of the recorded microseismic data shows a spatial concentration of microseismic activity on the western side of the investigated slope, and a correlation of these data with thermal information shows that the temporal concentration of the microseismic activity could be traced back to the transitions from warm to cold periods. Cold periods, characterized by a continuous and rapid temperature decrease in time, incurred a higher average daily number of microseismic events. [ABSTRACT FROM AUTHOR]

Needle-punched geosynthetic clay liner (GCL) specimens subjected to 0, 5, and 12 freeze–thaw cycles in the laboratory, and GCL specimens recovered from a composite barrier wall in the Canadian Arctic after 1 and 3 years were examined to assess the hydraulic conductivity/permeability with respect to both deionized deaired water and Jet A-l. The GCL specimens recovered from the field after 3 years had a hydraulic conductivity with respect to water that was approximately 30% less than that of the GCL specimens subjected to 12 initial freeze–thaw cycles in the laboratory, suggesting that the laboratory conditions are more severe than field conditions. The combined effects of both the freeze–thaw cycles and Jet A-l permeation increased the permeability. This increase is attributed to the creation of macropores in the GCL due to freezing and to an expansion of free-pore space due to contraction of the double layer caused by permeation of Jet A-l. Although there was an increase in permeability due to the combined effect of freeze–thaw and permeation by Jet A-l, the effect was relatively small and the results suggest that the GCL continued to exhibit good performance as a hydraulic barrier when subject to extreme climatic conditions and hydrocarbons both in the laboratory and in the field. [ABSTRACT FROM AUTHOR]

A three-dimensional moisture diffusion and volume change model was developed for determining the distribution of soil suction and the associated volume changes in an expansive soil mass under a covered area (e.g., slab foundations or pavements) with respect to time. The model was used to determine a relationship among the edge moisture variation distance, em, the amplitude of surface suction change, U0, and the diffusion coefficient of the soil, α. The edge moisture variation distance calculation is based on the change in soil suction beneath the covered area as a result of climate changes. The edge moisture variation distance is considered to be the distance between the edge of the covered area and the point beneath the covered area where suction change is no more than 0.12 kPa (0.1 pF). Comparison between the predicted values of edge moisture variation distance by using the proposed relationship to that measured in the field or predicted by other methods is also presented. [ABSTRACT FROM AUTHOR]

Keyblock stability in the "Snake Path" cliff of the Masada monument, situated on the western margin of the seismically active Dead Sea transform, is studied using field mapping, mechanical analysis, and monitoring of displacement, pressure, temperature, and relative humidity, over a period of 11 months. A linear nonreversible displacement trend is interpreted as the block response to regional microseismicity. A more pronounced cyclic displacement trend however is shown to be a response to climatic changes on the cliff face. This finding introduces a new, time-dependent, failure process in jointed rock slopes-the degradation of shear and/or cohesive strength of joints due climatic effects. Using two-dimensional (2-D) and three-dimensional (3-D) limit equilibrium analyses it is demonstrated that the 2-D solution overestimates the factor of safety against sliding by as much as 15% if water pressures in the boundary joints are considered. Application of a 2-D solution for a truly 3-D case where prismatic blocks are considered proves therefore to not be conservative. [ABSTRACT FROM AUTHOR]