Ground Settlement in Urban Structures Exposed to Geo-environmental and Anthropic Hazards: A Case Study for Galati

Abstract

A case study including a detailed ground settlement analysis is made for a particular loess structure located in the city of Galati, Romania, in order to assess the interdependence of geo-environmental and anthropic settlement triggering factors in the urban system context. In the first part of the study, loess behavior and its effects on built environment are analyzed and discussed based on worldwide historic expertise and current issues. An integrative analysis of loess deposits in natural state, with reference to induced-hydraulic and stress conditions, which was performed by laboratory and in-situ investigations, is then reported. An assessment of basic geotechnical parameters, as well as small-scale modeling of loess settlements at wetting under self-weight were conducted in order to select the most representative experimental area, from the point of view of specific soil structure behavior. Field monitoring surveys were performed to obtain information for quantitative evaluation of settlement time-dependent evolution, by the simulation of excessive moisture. The processing and analysis of experimental data gathered for natural and improved ground conditions revealed that the settlement amplitude of loess deposits with high sensitivity to wetting under self-load can be significantly reduced by the selection of adequate consolidation solutions, based on realistic and undisturbed environmental conditions. The study of soil structure behavior under simultaneous settlement-triggering factors can be integrated in multi-hazard analysis as a support for efficient strategies and mitigation measures, with applicability in the urbanization process, building and foundation design and environmental protection.