1,721,141 research outputs found
Rock Laboratory Tests
No full textLaboratory tests are carried out to determine rock properties. Since rock properties are a key input for rock mechanics design in civil, mining and petroleum engineering, the present chapter is mainly based on documents by the International Society for Rock Mechanics (ISRM). The ISRM Commission on Testing Methods since 1974 has published the ISRM Suggested Methods (SMs) covering different aspects of rock mechanics. The SMs are collected in books (‘yellow’ book, Brown 1981; ‘blue’ book, Ulusay and Hudson 2007; ‘orange’ book, Ulusay 2015). A complete list of ISRM SMs is included in the ‘orange’ book. The content of the present entry does not presume to provide detailed instructions on the test procedures or to be exhaustive of the rock laboratory tests. The reader is invited to refer to the above-mentioned ISRM books. Moreover, not only are rock laboratory tests numerous, but the work of the ISRM Commission on Testing Methods is always in progress and further SMs on different tests or updated procedures will be published
Analysis of deformations occurring at the edge of a rock cliff underneath a historical center
No full textThe gate of the ancient town of S.Leo is located at the edge of an overhanging rock cliff, over 60 m high, consisting of calcarenites with siltstone beds. The cliff borders a rock butte overlying a tectonized clay substratum. Both the rock slab and the substratum are characterized by a structural complexity at different scales. A comprehensive analysis of numerical models and of in situ surveys and monitoring results suggest that the upper part of the cliff is affected by deformations, which can be seen as a part of a flexural toppling mechanism. At present the instability phenomenon is characterized by small but continuous deformations. Despite its slow rate, which is also due to the remedial measures carried out during the last years, its evolution has to be carefully monitored. The structural integrity of the ancient buildings is in fact to be preserved, and the long term effects of the severe state of stress induced by the morphological conditions can not be underestimated
Multiscale physical and mechanical characterization of a sandstone used as armourstone
No full textThe suitability of a sandstone from Central Italy as armourstone source was investigated both at the specimen and block scale. Once the physical properties were determined, the rock material was subjected to ultrasonic pulse, mechanical and wear/durability tests. The results were linked to the petrographic features observed at the optical and scanning electron microscope. Possible defects in blocks were investigated through drop tests and by comparing wave velocities measured on specimens and blocks. The rock has good physical, mechanical and durability index properties, whilst its wear resistance addresses the use of blocks in moderately stressing conditions (e.g. internal harbour areas). Blocks can be downgraded if affected by diffuse oxidation, as it is associated to a reduction of physical and mechanical properties. © 2024 The Author(s)
Evoluzione delle deformazioni di una frana di scivolamento in calcari con interstrati, periodicamente riattivata dalle precipitazioni
No full textTwenty-year monitoring of the Orvieto overconsolidated clayey slope (Italy)
No full textIn addition to landslides of different types and extent, the clayey slope of the Orvieto hill is affected by extremely slow movements at relatively high depths (up to 33 m) and by very slow movements at shallower depths (up to 10 m). These movements are strictly re-lated to rainfall regimes and to the consequent pore pressure distribution inside the hill. The influence of rainfall regimes on the hy-draulic conditions and movement rates was reconstructed by means of piezometric and inclinometric measurements performed overthe last twenty years
Geotechnical properties of Soft Clayey Sediments from the Submerged Tiber River Delta, Italy.
No full textThe geotechnical properties of the fine-grained sediments of the Tiber River prodelta slope are described. Laboratory investigations depict the overall physical and mechanical behavior of the sediments and give information regarding their in-situ conditions due to gravitational campaction. In spite of relative homogeneity in terms of the basic geotechnical properties, noticeable differences between materials sampled at different water depths and at different depths below the seafloor can be detected. This variation is observed when in-situ material properties are taken into account and can be explained if the different depositional and burial conditions of the sediments are considered. In particular, differences in compressibility and undrained behavior have been found between sediments sampled immediately underneath the seafloor and the underlying materials as well as between the entire present-day prodelta clays and the "aged" sediments of the delta front, which were originally deposited in a prodelta slope environment. These considerations cart be generalized to other small marine deltas, which are not characterized by the exceptional depositional rates typical of the extensively studied large deltas but frequently occur worldwide and host offshore engineering activities
Physical and mechanical characterization of the soft pyroclastic rocks forming the Orvieto cliff
Full text linkThe paper describes the results of laboratory and in situ investigations carried out on weak pyroclastic materials which could be encountered during engineering activities in volcanic regions. The research was focused on the historical town of Orvieto, representing a typical geotechnical situation which is widespread in Central Italy. The in situ investigations include cross-hole and SASW measurements performed in adjacent areas. The laboratory tests provided static and dynamic properties which were compared to the in situ data, in order to reconstruct the geotechnical model of a representative area of the town
Caratterizzazione dell’ammasso roccioso di fondazione di una diga in presenza di discontinuità con riempimento
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