Climate eff ects rela ng to air temperature, radia on, snow cover, and rainfall combine with thaw and infi ltra on processes to cause changes in the thermal response and associated creep deforma ons in rock glaciers, which are the geomorphological expression of Alpine permafrost. The annual surface creep of some rock glaciers has accelerated recently by an order of magnitude. A mul disciplinary fi eld study links characteriza on, monitoring, and modeling for such a rock glacier in the Turtmann valley in Switzerland. The fi rst phase consisted of characteriza on using seismic refrac on and ground-penetra ng radar (GPR), as well as borehole informa on and monitoring of meteorological, hydrothermal, and geotechnical variables over 2 yr. The ground model confi rmed the heterogeneity of the internal structure, with rock glacier topography aff ec ng the thermal distribu on in boreholes and seepage fl ows from tracer tests at between 10 and 40 m h −1 . Temperatures were generally warmer than −0.25°C in the permafrost zone, with some variability in terms of thermal degrada on of some layers to 0°C and an ac ve layer of about 3 to 5 m depth. Unique internal shear movements were measured by an automa c inclinometer, which indicated downslope creep rates in the shear zone and at the surface of about 2.4 and 3.2 m yr −1 respec vely, which could not be directly linked to temperature at the same depth. These rock glaciers have poten al for future instability, which could damage infrastructure in the valley below. It is essen al to understand why they have accelerated over the past decade through the complex interac ons that have controlled the thermo-hydromechanical response.

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For historical buildings with a worth-preserving appearance, internal wall insulation can be the only possible solution to improve the building energy efficiency. However, the application of an internal insulation layer changes significantly the hygrothermal performance of the building envelope. For masonry walls, such intervention may lead to freeze-thaw damage of the brickwork. In this study, a hygrothermal model is developed. The model takes into account moisture and heat transport in porous medium and tracks the occurrence of freezing and thawing in function of pore size distribution and as well as the ice content. Freezing and melting of water in porous medium is implemented based on the theory of freezing point depression, as freezing temperature of water in porous medium depends on pore size, i.e. water in the smaller pores freezes at temperatures lower than 0° C. The numerical model results are compared with a porous medium freezing experiment and good agreement is found. Traditional hygrothermal assessment uses the number of zero crossings on a Celsius scale as the number of freeze-thaw cycles. We propose a method that uses the number of actual ice growth and melt cycles as an indicator more accurately accounting for the freeze-thaw process. In addition, we develop an index, called FTDR Index, to assess freeze-thaw damage risk. We perform simulations of uninsulated and internally retrofitted masonry walls using two Swiss climatic conditions. The study clearly shows increase of freeze-thaw cycles and ice content after internal retrofitting in both climates. Thus, FTDR Index increases after internal retrofitting.

The freezing temperature of water in soil is not constant but varies over a range determined by soil texture. Consequently, the amounts of unfrozen water and ice change with temperature in frozen soil, which in turn affects hydraulic, thermal, and mechanical properties of frozen soil. In this paper, an Am-241 gamma ray source and time-domain reflectometry (TDR) were combined to measure unfrozen water content and ice content in frozen soil simultaneously. The gamma ray attenuation was used to determine total water content. The TDR was used to determine the dielectric constant of the frozen soil. Based on a fourphase mixing model, the amount of unfrozen water content in the frozen soil could be determined. The ice content was inferred by the difference between total water content and unfrozen water content. The gamma ray attenuation and the TDR were both calibrated by a gravimetric method. Water contents measured by gamma ray attenuation and TDR in an unfrozen silt column under infiltration were compared and showed that the two methods have the same accuracy and response to changes of water content. Unidirectional column freezing experiments were performed to apply the combined method of gamma ray attenuation and TDR for measuring unfrozen water content and ice content. The measurement error of the gamma ray attenuation and TDR was around 0.02 and 0.01 m 3 /m 3 , respectively. The overestimation of unfrozen water in frozen soil by TDR alone was quantified and found to depend on the amount of ice content. The higher the ice content, the larger the overestimation. The study confirmed that the combined method could accurately determine unfrozen water content and ice content in frozen soil. The results of soil column freezing experiments indicate that total water content distribution is affected by available pore space and the freezing front advance rate. It was found that there is similarity between the soil water characteristic and the soil freezing characteristic of variably saturated soil. Unfrozen water content is independent of total water content and affected only by temperature when the freezing point is reached.