Landslide processes and stability assessment in weathered carbonate rock cliffs

Many sites of the Apulian coast (southern Italy) consist of carbonate rock cliffs affected by intense erosion and development of slope instabilities. Present morphology of the coastal cliffs was mostly produced by the quaternary tectonics, and the severe and selective action of erosion by sea waves. In addition, due to the carbonate nature of rock masses, the role exerted by development of karst processes has to be considered. The cliffs are involved in different types of landslides, with several, complex mechanisms of rock slope failure. Assessment of the overall slope stability, and evaluation of the potential hazard, are related to the morphologic, lithologic, and structural characteristics of the rock cliffs, and to local meteomarine condition and erosion by sea waves as well. This article provides a critical review of the common modes of failure in weathered and soft carbonatic rocks; the different theoretical formulations that allow predictions about the behavior of rock slopes are also examined. Examples of slope hazard indicators and mass movement typologies are in particular illustrated along a typical apulian area (stretch of Murgia coastline south of Bari)

The effects and importance of anthropogenic changes on karst environment

This paper describes a case study in the Murge karst (Apulia, southern Italy) in a site in which the role exerted by anthropogenic activity, in the course of the time, has caused significant damage to the natural landscape and environment, also in terms of loss of human life. Recently, in the night between 22 and 23 October, 2005, exceptional rainfalls (160 mm in a few hours, in an area where the mean annual rainfall is about 600 mm), hit the city of Bari and the neighbouring towns, belonging to the same catchment area. The heavy rainfall caused a flood event with disastrous results: six dead and the destruction of roads, railways and bridges. The whole area is characterised by a low-relief karst very rich in natural cavities and slightly incised valleys, the latter locally called “lame”. These karst valleys act as water flow channels only during and immediately after heavy rainstorms and, in the coastal area, generally, reach the shoreline. Karst morphology is very well developed due to widespread outcrops of Cretaceous carbonate rocks of the Apulian foreland. In recent years, urbanization, land use change and quarrying produced irreversible degradation and serious consequences for the the integrity of the fragile natural landscape. Starting from medium-term in situ observations, detailed surface surveys, historic and bibliographic data (archival terrestrial photographs and scientific papers), and aerial photograph analysis, this study provides a description of the main factors influencing the geomorphologic processes affecting a typical karst area including hydrological, geological and anthropogenic control on landscape development

Degree of decay and weathering mechanisms in the ancient walls of Castro (Salento, southern Italy)

The ancient centre of Castro is located on a hill ridge along the coastal area of Salento (southern Italy). It is known for the beautiful landscape and historic heritage date back to the Upper Palaeolithic (wall-paintings inside the coastal cave, locally called “Grotta Romanelli”). The medieval walls surrounding the ancient centre are now in a deteriorated state owing to weathering by wind action, marine aerosols and meteoric water precipitations. The historic structure is, in fact, exposed to marine environment. Calcarenite rocks, which outcrop along the coastal stretch about 5 km N of the historic centre, constitute the building stones of the ancient walls. These rocks are very soft and porous and show a reduced ability to maintain their characteristics of strength, appearance, and resistance to decay over a considerable period of time. In order to evaluate the degree of decay of the building stones, petrophysical and mechanical analysis were performed on both fresh (from original quarry) and deteriorated specimens. The study involves, particularly, microtextural analysis on thin sections using optical petrographic microscopy, and evaluation of index parameters by means of standard geotechnical laboratory tests. Particular attention is given to pore size distribution by mercury intrusion porosimetry, effective porosity and degree of saturation by water absorption determinations, grain size frequency distribution by traditional sieve and sedimentation analysis on disaggregated materials

Hazards related to open pit quarries in the karst environment of Apulia, south-eastern Italy

The Murge plateau (in the Apulia region of south-eastern Italy) is characterized by a Mesozoic sedimentary succession of regularly stratified fine-grained limestones. These materials exceed 6000 m in thickness, and are overlain by Plio-Pleistocene transgressive calcarenites. The peculiar geologic setting, and especially the widespread presence of carbonate rocks, determined the intense development of karst processes. Great part of the region is in fact characterized by karst morphology and the presence of a complex network of underground cavities and caves. Many carbonate rocks in the area have been extracted in the past for construction purposes and as building materials. The intense extractive activity was principally localized in open pit quarries. Today, several quarries are still active, while, on the other hand, a number of them has been abandoned. Although Italian legislation provides quarry restoration at the end of exploitation, many of the abandoned quarries cause relevant environmental alteration and damages, and high hazards as regards slope instability problems and pollution. This paper deals mostly with the analysis of the factors controlling the different types of landslides (slides, falls, topples, etc.) in selected abandoned quarries of the Murge plateau. In particular, an effort will be made to evaluate the influence of the textural and geostructural features on slope stability in carbonate rock masses which are intensely affected by karst processes. Examples of rock slope failure mechanisms are illustrated at different scales. A new rock mass classification method for engineering design and a simple theoretical model for slope stability assessment is proposed

Influence of weathering, textural and geostructural features in slope stability analyses for limestone open pit quarries

The Murge plateau (Apulia, south-eastern Italy) is characterised by a Mesozoic sedimentary succession (exceeding 6000 m in thickness) of regularly stratified fine-grained limestones overlain by Plio-Pleistocene transgressive calcarenites deposited in shallow and agitated marine waters. This particular geologic setting has favored today, as in the past, an intense extractive activity, principally localized in open pit quarries. Although Italian legislation provides quarry restoration at the end of exploitation, many quarries were abandoned causing relevant environmental alteration and damages, and high risk situation for slope instability. Factors controlling the different types of landslides (slides, falls, topples, etc.) are described. In particular, the influence of textural and geostructural features on slope stability in carbonate rock masses affected by karst are analysed. Examples of rock slope failure complex mechanisms are illustrated at different scales. A new rock mass classification method for engineering design and a simple theoretical model for slope stability assessment is proposed

Shallow landslides in weathered soils: a case study from the Apennine chain in southern Italy

Stability conditions in an area located at the eastern Daunia Mts. are presented in this study. The Daunia Mts. belong to the outermost part of the southern Apennine chain, which consists of a Neogene thrust belt resulting from the deformation of the Apulian continental margin. In particular, the study area, in the territories of Alberona, Volturara Appula and San Bartolomeo in Galdo, is located at the north-western boundary of Apulia (southern Italy) in one of the most seismic zones of Italy. It is characterised by low structural and topographic elevation, only locally exceeding 1000 m above sea level. The geological setting is very complex and represented by a series of tectonically deformed turbiditic formations of pre-Pliocene age covered by discontinuous Quaternary and Holocene deposits, including terraced alluvial deposits and colluvial slope sediments. The outcropping units are rich of weathered argillaceous deposits in chaotic setting and prone to landsliding. The area is affected by intense landslide activity, mostly related to periods of heavy and prolonged rainfalls (mean annual rainfall is above 600 mm). The most common types of mass movement are shallow slips, flows and complex landslides consisting of rotational slumps evolving to flows. They are mainly re-mobilisations of shallow landslides involving weathered clayey soils. This study presents the site characterisation, including geology and hydrogeology, assessment of the pore pressures and soil properties, especially shear strength parameters for both drained and undrained conditions, mechanics of sliding, and analysis of stability, slope hazard and deformations pre- and post-failure. In particular, an attempt will be made to evaluate the weathered characteristics of the formations involved in landsliding

The Karst of Salento Region (Apulia, Southern Italy): Constraints for Management

Polotok Salento je kraško območje s precejšnjim tveganjem, povezanim s površinsko in podzemno vodo. Da bi preprečili poplavljanje, so velike količine površinskih voda kanalizirali v vrtače. Zaradi tega je v zadnjih letih na večih mestih prišlo do hitrega pogrezanja in udiranja tal. »lanek obravnava dve področji, kjer je do tega prišlo.The Salento peninsula is a karstic area affected by relevant geological risk mainly due to surface water and groundwater. In particular, sinkholes have been used to convey underground large amount of surface waters (rain water, waste water, etc.) aiming to avoid the flooding of wide land surfaces. However, during the last ten years this input of surface water underground has caused several cases of rapid subsidence. In this paper, the detailed study of two areas which have been recently affected by rapid subsidence is reported

Physiotherapy management of lower limb osteoarthritis

© The Author 2017. Published by Oxford University Press. Background Osteoarthritis (OA) of the lower limb affects millions of people worldwide, and results in pain and reduced function. We reviewed guidelines and Cochrane reviews for physical therapy interventions to manage the condition. Sources of data Evidence from meta-analyses and systematic reviews was included. We also identified the recommendations from guidelines relevant to practice in the UK. Areas of agreement There is strongest evidence to support the use of exercise to improve pain, function and quality of life. Areas of controversy There is limited evidence to support the use of some commonly utilized physiotherapy interventions. National Institute for Health and Clinical Excellence do not recommend the use of acupuncture. Growing points Programmes that include single exercise type may be more beneficial than combined strengthening and aerobic interventions. Areas timely for developing research Further research is required to determine how to facilitate long-term engagement with exercise to sustain the beneficial effects on pain, function and quality of life. Studies that investigate packages of care, combining interventions require further investigation