Stabilization of clayey soil using fibre reinforcement

The paper presents experimental and numerical investigations on crack evolution during desiccation, on unsaturated, compacted and reinforced clay using natural Alfa fibres. The effect of fibre content is investigated and a comparison between experimental and numerical simulations is made. A modified model for tensile strength is updated in the finite element program CODE_BRIGHT and used to predict tensile cracks induced by desiccation on reinforced soil. The results show that the soil desiccation cracking behaviour is significantly influenced by fibre inclusion and that experimental and numerical results are in good agreement.Postprint (published version

Shear Failure Criterion Based on Experimental and Modeling Results for Fiber-Reinforced Clay

International audienc

Quantification of hysteresis effects on a soil subjected to drying and wetting cycles

A quantitative description of soil hysteretic response during drying-wetting cycles is required to improve prediction of the soil water retention model. The objective of the study is to quantify the degree of hysteresis, which is helpful to evaluate the precision of soil water flow calculation. A new procedure to quantify the degree of hysteresis is presented. The Arya-Paris model allows assessment of hysteresis effects from initial drying curves, dynamic contact angles, degree of hysteresis value, and maximum difference value between drying and subsequent wetting curves. The experimental results show that the degree of hysteresis varies with the particle size, bulk density, void ratio, initial water content, and contact angle of the soil. The new findings can be very useful in modelling soil water flows

Analysis of slope movement initiation induced by rainfall using the Elastoplastic Barcelona Basic Model

In some arid and semi-arid regions, different types of infrastructure assets suffer from degradation of the roads, the embankment failures, erosion due to cyclic hydraulic actions and the effects of rainfall infiltration on slopes. Typical cases, such as the national roads in the north-west of Tunisia (Beja city) have been affected dramatically. Recent landslide is manifested in this region, especially in a plastic clay soil. Stability problems are caused by soil saturation and the presence of abundant cracks which are developed after a long dry summer. In fact, due to geotechnical problems, the annual loss due to the damage is estimated at $1 million in Beja area (30 km(2)). The effect of rainfall infiltration into the unsaturated clay during wet seasons characterised by either long duration low intensity rain or short duration high intensity rain have been analysed. The elastoplastic Barcelona Basic Model (BBM) has been used and soil movements leading to slope failure were calculated according to the unsaturated state evolution. The effects of cyclic hydraulic paths on the yield function have also been investigated. The yield function evolution depends on the cohesion and the apparent consolidation stress variations. The numerical calculations were evaluated against the field measurement displacements.Peer Reviewe

Social sustainability Gender and household relations in two forestry communities in Quintana Roo, Mexico

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN038472 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A study of the slope stability in unsaturated swelling marly clay

The analysis of the some experimental field data on the unsaturated unstable slope constituted with a marly clay soil showed that the swelling and collapse phenomena were the origin of the landslide problem. In the studied case, field investigation data and laboratory tests based on the water retention curve determination were analysed. The recorded pore-water pressure field helped us to identify the hydrological conditions. In fact, the wetting and drying cycles involve the total suction and the degree of saturation changes. To predict the shallow slope failure, a constitutive model taking into account the suction effect as well as their dependence on degree of saturation is proposed. It is especially remarkable that the collapse phenomenon is well reproduced when the model incorporates suction changes and saturated preconsolidation stress. The analysis of the slope failure, basing on the field data and the theoretical study, shows the hydraulic and mechanical effects

Stabilization of clayey soil using fibre reinforcement

The paper presents experimental and numerical investigations on crack evolution during desiccation, on unsaturated, compacted and reinforced clay using natural Alfa fibres. The effect of fibre content is investigated and a comparison between experimental and numerical simulations is made. A modified model for tensile strength is updated in the finite element program CODE_BRIGHT and used to predict tensile cracks induced by desiccation on reinforced soil. The results show that the soil desiccation cracking behaviour is significantly influenced by fibre inclusion and that experimental and numerical results are in good agreement

Some investigations about the tensile strength and the desiccation process of unsaturated clay

The current paper presents an investigation on the tensile strength of unsaturated clay, and a discussion about the significant differences between the behaviours of compacted soils and those of the completely remoulded soils. The adapted experimental device based on the shear box for the measurement of the tensile strength is also presented. In the tensile tests, stress-strain characteristics are measured using high precision transducers and electronic data acquisition. The equipment is capable of measuring tensile strengths of soil (about 10 MPa). Moreover, a new model to predict cracks is presented in 3D. This analytical model for the prediction of tensile strength, as a function of suction and porosity, is given

Detection of the reinforcement and the prestressing cables in concrete members and structures

Translated from Spanish (Bol. Inf. Lab. Transp. M. S. 1973 (95) p. 49-73)Available from British Library Document Supply Centre- DSC:9057.2457(TRRL-Trans--3561)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo