Assessing the potential damage to unreinforced masonry (URM) buildings under soil subsidence is a complex task, due to several factors associated with URM mechanical behaviour and soil-structure interaction. The remarkable variability in material properties of masonry may be further exacerbated by degradation processes, with repercussions on the overall structural response. Furthermore, both in-situ surveys and laboratory tests point out a major role being played by bond pattern effects and strength ratios between masonry constituents on crack formation, distribution and progression. Advanced numerical methods such as those based on masonry micro-modelling might be employed to realistically account for such factors, explicitly incorporating material discontinuities, fragmentation, and collision. In this paper, the Applied Element Method (AEM) is used to simulate the nonlinear structural response and damage of two tuff stone masonry walls with opening, which were experimentally tested under soil settlement in intact and deteriorated conditions. A satisfactory numerical-experimental agreement is found, allowing damage propagation phenomena as well as load redistributions between structural elements to be captured. Such results can then be used as a basis to perform further investigation considering more complex scenarios at structural scale.

Desiccation cracking has a significant impact on the hydro-mechanical properties of soils, yet quantifying crack patterns remains challenging. This study presents a quantitative framework with a total of 26 parameters for characterizing the geometric and morphological characteristics of soil desiccation crack patterns, including soil clod parameters (soil clod area, soil clod perimeter, number of clods, and the probability density distribution of clod parameters, etc.) and crack network parameters (crack length, crack width, crack inter angle, number of crack segments, surface crack ratio, crack density, connectivity index, etc.). To implement this quantitative framework, the Crack Image Analysis System (CIAS) was developed to automatically identify and analyse complex crack patterns through image preprocessing, clod identification, crack network identification and batch processing. CIAS was then applied to quantify the crack images of soil with different thicknesses, validating its efficacy. To comprehensively describe the geometric and morphological characteristics of crack networks, it is recommended to use the number of soil clods per unit area, surface crack ratio, crack density, and connectivity index as key parameters. These metrics effectively capture information on crack spacing, area, length, width, and connectivity. This comprehensive framework for characterizing and quantifying crack images is of great significant for geological engineering. Moreover, it holds great potential for application in other different disciplines such as geotechnical, hydraulic, mineral engineering and material even planetary science.

This paper aims to assess the ultimate bearing capacity of a strip footing on the ground surface of a silty sand soil layer. It considers structural failures and geotechnical changes, including the impact of moisture content, using numerical simulation in PLAXIS 3D V21. The structural damage assessments on a student center building located in the northern part of Peninsular Malaysia were performed by visual inspection, and thirty-six sub-points of rebound hammer tests were conducted on three selected different points (Point 1, 2, 3) of the building to evaluate concrete strength and record crack characteristics for severity classification. Subsequently, an extensive geotechnical laboratory tests were performed to investigate the effects of moisture content on physical and mechanical properties of silty sand including, soil compositions, Atterberg limits, compaction characteristics and unconfined compressive strength (UCS) from the building area which resulted to structural damage caused by differential settlement beneath the building. The visual inspection assessment has shown the student center building experienced severe damage category at Point 1 with crack width and length are 25 mm and 3 m respectively. At Point 2, there was minimal damage to the surface structure, with a crack measuring 1 mm in diameter and 0.1 m in length. Furthermore, crack width and length are 1 mm and 0.2 m respectively are recorded for Point 3. The study fills in a gap in the research by combining geotechnical and structural tests on the bearing capacity of silty sand with moisture content. The effect of soil saturation, matric suction, and the unsaturated strength of soil are affected by these factors in the analysis of the bearing capacity of the foundation. The exact solution gives us 568.213 kPa for a zero degree of saturation and 385.34 kPa for a 100 percent degree of saturation. The incorporation of geotechnical and structural assessments aims to find reliable strategies for failure remediations for instance patched and sealed with a concrete patching compound.