In this paper some information concerning the geotechnical characterisation of several sites of the city of Catania have been presented. In situ investigations of sandy harbour soils were therefore carried out in order to determine the soil profiles and the geotechnical characteristics for potential liquefaction evaluation under cyclic loading. The CPT results are generally more consistent and repeatable than results from other penetration tests. The continuous profiles i.e. for the city of Catania also allow a more detailed interpretation of soil layers and soil types. Thus the CPT can be used to develop preliminary soil and liquefaction resistance profiles for site investigations. Semi-empirical procedures for liquefaction evaluations originally have been also developed using the Standard Penetration Test (SPT) to differentiate between liquefiable and nonliquefiable sites. Criteria for evaluation of liquefaction resistance based on standard penetration test (SPT) blowcounts have been rather robust over the years. Seismic Dilatometer Marchetti Tests (SDMT) have been also carried out, with the aim to evaluate the soil profile of shear wave velocity (Vs) and the horizontal stress index (Kd). The available data obtained from the Seismic Dilatometer Marchetti Tests results enabled also to evaluate the potential liquefaction. The Seismic Dilatometer Marchetti Test (SDMT) has the advantage, in comparison with CPT and SPT tests, to measure independent parameters, such as the Horizontal Stress Index (Kd) and the shear wave velocity (Vs). The use of the shear wave velocity, VS, as an index of liquefaction resistance, illustrated by several authors, has been also compared with the other approaches based on CPT, SPT or SDMT test results on sandy soils for potential liquefaction evaluation.

The cap cover of a municipal solid waste landfill, must ensure the containment of the wastes, control rainwater infiltrations and limit biogas leakage to the atmosphere. The specific characteristics of the cap cover are necessary to be maintained during all the lifespan of the landfill, despite the loadings to which it is subjected to: mechanical stresses, hydraulic load changes, physico-chemical variations and changes of climatic conditions. The water transfer through the clayey geomaterials, geosynthetic clay liners (GCL) installed as capping in landfill, is studied at three different scales. In-situ large scale experiments, laboratory experiments and intermediate scale experiments were conducted. Barriers remained effective after two years following installation. Percolation rates were less than 1% of the rainfall and the ion exchange in the GCL was 180 times lower than the initial. However, hydraulic conductivity increased slightly due to desiccation.

Relationships between soil type names written in the borehole logging data and fines content are investigated based on a statistical analysis of the estimation of the liquefaction strength determined without conducting a grain size analysis. Approximately 7700 borehole logging data sets were collected in the Miyagi Prefecture including Sendai City, Japan and approximately 1500 of these were selected for grain size analysis. These include 4409 results of grain size analyses and there are a total of 392 soil names. Soils were classified into 17 major soil types (gravel to clay, fill, surface soil, etc.); fines content was found to scatter significantly and there were significant difference between the investigated data and the representative value used in practical applications. Then, further classification was made in terms of adjectives such as "sandy", "silty", "with sand", "with silt", etc., and the average fines contents and standard deviations were investigated. Significant variations were found in the fines content distribution between the soils, even within the same major classification. Finally, several case studies were carried out to show the effect of the soil type on the liquefaction resistance strength (FL value). This showed the importance of the grain size analysis because liquefaction strength is highly sensitive to the Fc value.

Christchurch and the Canterbury region in New Zealand were devastated in 2010-2011 by a series of powerful earthquakes. The Christchurch area experienced widespread liquefaction that caused extensive damage. One critical problem facing the rebuilding effort is that the land remains at risk of liquefying in future earthquakes. Therefore, effective engineering solutions had to be developed to increase the resilience of homes and low-rise structures. To this end, a comprehensive series of full-scale field trials of multiple shallow ground improvement methods was performed. The field trials presented in this paper were conducted at one area in a severely damaged suburb of Christchurch and involved five test panels of different ground improvements. Each test panel and two additional test panels of unimproved natural soil were instrumented with embedded arrays of sensors and were characterized by crosshole seismic testing before shaking. A large mobile shaker, called TRex, was used to perform a staged-loading sequence of increasing sinusoidal horizontal loads at the surface of each test panel. The results of the staged-loading tests were successfully used to identify ground improvement methods that improved the ground performance versus those methods that contributed an insignificant improvement or even degraded the ground performance. The results of the pre-shaking crosshole tests were successfully used for two purposes.First, portions of the soils below the water table that were unsaturated were identified using compression wave velocities. Second, shear wave velocities were used: (1) to identify changes in the natural soil skeleton between improvements, and (2) to evaluate the effective shear stiffness of the combined improvement and surrounding natural soil. Further, the crosshole measurements led to development of a field verification method for use in evaluating changes created by shallow ground improvements.

A relevant issue in the physical and hydromechanical behaviour of lime treated soil is the physico-chemical evolution of the system and its influence on the microstructural features of the treated soil. In the present study a multi-scale investigation on the short and long term effects of a lime treated kaolinite has been performed. Aim of the experimental work is the analysis of the link between the ongoing of the reactions induced by lime and the macroscopic evolution of soil properties. Some of the results obtained by means of oedometer tests on not treated and lime stabilised samples have been presented in the paper. The mechanical tests were complemented by investigations at microscopic level. The mineralogical changes induced by lime addition were monitored at increasing curing time by means of thermogravimetric analysis (TGA). The effects of lime addition on the clay particles arrangement were investigated by means of zeta potential and dynamic light scattering (DLS) measurements. Test results reveal a low reactivity of lime treated kaolinite to promote the development of pozzolanic reactions. The formation of hydrated phases was observed only starting from 28 days of curing proving that the improvement of soil properties is ruled by microstructure and not by bonding compounds resulting from pozzolanic reactions.