1. Characteristics of dynamics problems 2. Characteristic changes in cyclic stress in typical dynamic loading environments 3. Methods of representing stress-strain relations in cyclic loading 4. Apparatus and procedures for laboratory tests 5. In-situ survey by wave propagation 6. Low-amplitude shear moduli 7. Strain-dependency of modulus and damping 8. Effect of loading speed and stiffness degradation of cohesive soils 9. Strengths of cohesive soils under transient and cyclic loading conditions 10. Resistance of sand to cyclic loading 11. Sand behaviour in monotonic loading 12. Evaluation of liquefaction resistance by in-situ soundings 13. Analysis of liquefaction 14. Settlement in sand deposits following liquefaction 15. Flow and on-flow conditions and residual strength 16. Onset condition for liquefaction and consequent flow Appendix: Methods of sample preparation Index

Soil behaviour in earthquake geotechnics

A unique relationship determining strength of silty/clayey soils – Portland cement mixes

The paper presents the development of a three-dimensional finite-element model for pile tests in dense Dunkirk sand, conducted as part of the PISA project. The project was aimed at developing impro...

https://www.icevirtuallibrary.com/doi/pdf/10.1680/jgeot.18.PISA.006

Finite-element modelling of laterally loaded piles in a dense marine sand at Dunkirk

Based on a large database of unconfined compressive strength (qu) and splitting tensile strength (qt) results of cement-bonded clean granular soils with varying characteristics, distinct po...

Broad-Spectrum Empirical Correlation Determining Tensile and Compressive Strength of Cement-Bonded Clean Granular Soils

Responses of deep soil layers to combined recharge in a leaky aquifer

Present research aims to carry out field and laboratory tests in a top cement improved residual soil layer. Regarding laboratory tests, the isolated influence of parameters such as cement percentage, porosity and water content will be studied after unconfined compression testing. Test results showed that the unconfined compressive strength (qu) increased along with the cement percentage and with the reduction of the porosity of the compacted mixture. It was still possible to verify that the water content had reduced influence on the unconfined compressive strength, which was basically dependent of porosity and amount of cement. The research also studied the behavior of plate load tests with different diameters (D) bearing on a treated layered system with different thickness (H) considering 5% of portland cement (determined after analysis of unconfined compression test results). Triaxial tests were also carried out in specimens retrieved from the cement treated layer, cone penetration tests (CPT) were done in the cement improved layer and the outcome shows a substantial increase in tip cone resistance comparatively with the natural soil. A finite-element analysis of the plate load tests was carried out using the elastic-perfectly plastic model with Drucker-Prager failure criterion that proved suitable for the simulation. After processing results of plate load tests bearing on the cemented layered system, it was verified that the applied pressure versus settlement to diameter ratio correlation is controlled by the H/D relation, in which this factor increase takes to a stiffer and stronger response. DOI: 10.1061/(ASCE)MT.1943-5533.0000725. © 2014 American Society of Civil Engineers. Author keywords: Porosity/cement ratio; Shallow foundations; Cemented soil; Cone penetration test; Layered soils; Numerical simulation.

Testing Cement Improved Residual Soil Layers

Derivation of model parameters for numerical analysis of the Ivens shaft excavation

This paper compares two-dimensional (2D) with three-dimensional (3D) water flow modelling used to predict the behaviour of an embankment built on a soft soil improved with prefabricated vertical drains. The three-dimensional analysis is performed considering the field pattern of the vertical drains, whereas in the two-dimensional analyses the verticals drains are simulated in two ways, using an equivalent overall permeability and considering the draining walls. The numerical predictions are compared with one another and with the field data in terms of settlement, horizontal displacement and excess pore pressure. The two-dimensional analyses provide similar results to the three-dimensional modelling in terms of settlement and horizontal displacement. Naturally, the time evolution of the excess pore pressure depends on the drainage conditions, which differ in the cases studied. In general, it is concluded that the use of two-dimensional modelling, employing an equivalent overall permeability, is sufficientl...

Numeric modelling of vertical drains: two- and three-dimensional analyses

The design of complex underground structures in an urban environment requires in the first instance an appropriate characterization and interpretation of the ground conditions and of the mechanical behaviour of soil formations in the ground profile. With such information it is then possible to select and calibrate appropriate soil constitutive models for application in advanced numerical analysis, with the objective of predicting the induced ground movements and the potential damage to existing structures and services. This paper provides an interpretation of the site investigation data collected for the numerical analysis and design of the Ivens shaft excavation in Lisbon, Portugal. For the first time a comprehensive set of interpreted data is obtained for two of the main formations in the Lisbon area, Argilas e Calcarios dos Prazeres (AP) and Areolas da Estefânia (AE), improving the understanding of their mechanical behaviour and making the data available for application in most soil constitutive frameworks. It is evident from the results that even with careful testing procedures the data may appear to be inconsistent, requiring further assumptions when deriving soil parameters. Such assumptions are discussed and emphasis is placed on the need to combine data from laboratory and field investigations.

/pdf/geotechnical-characterization-of-the-miocene-formations-at-342zrow1ki.pdf

Geotechnical characterization of the Miocene formations at the location of Ivens shaft, Lisbon

Fundacao para a Ciencia e a Tecnologia - Programa POCTI/ECM/2521/95 - Concepcao, Projecto e Reabilitacao de Tuneis em Obras Viarias.

https://repositorium.sdum.uminho.pt/bitstream/1822/4497/1/Tunel4-RevGeo99.pdf

Jorge Almeida e Sousa

Papers

Testing Cement Improved Residual Soil Layers

Derivation of model parameters for numerical analysis of the Ivens shaft excavation

Numeric modelling of vertical drains: two- and three-dimensional analyses

Geotechnical characterization of the Miocene formations at the location of Ivens shaft, Lisbon

Túnel 4 (Porto) : análise tridimensional por elementos finitos