Embedment

About: Embedment is a research topic. Over the lifetime, 2441 publications have been published within this topic receiving 31444 citations.

Bond of reinforcement in self-compacting steel-fibre-reinforced concrete

Abstract: Crack control, one of the main benefits of using fibre reinforcement, depends to a large extent on the concrete-rebar bond. Pull-out tests of specimens with short embedment length were carried out and the results showed no effect from the fibres on the normalised bond-slip behaviour before peak load. After this, the fibre reinforcement provided extra confinement, changing the failure mode from splitting to pull-out failure. The test results were used to calibrate a finite-element bond model that considers both tangential stresses and stresses in the radial direction from the rebar. Splitting cracks may be thus considered in the finite-element analyses. The model proved to yield results in good agreement with the experimental results regarding failure mode, load-slip relation and splitting strains on the surfaces of the pull-out specimens. The analyses revealed that two types of action were active in the cracking process. In addition, the confinement effect of the fibre reinforcement was compared with the confinement of conventional stirrups using the bond model in CEB-FIP model code 2010.

Three-dimensional numerical modelling of discrete piles used to stabilize landslides

Abstract: Three-dimensional finite difference analyses have been carried out to investigate the behaviour of a single pile used to stabilize a slipping mass of soil by embedment into a stable stratum. Analys...

Computations of uplift capacity of pile anchors in cohesionless soil

Abstract: A method of analysis for the uplift capacity of pile anchors in cohesionless soil is proposed using Kotter’s equation that facilitates computation of the distribution of soil reaction on the axis-symmetric failure surface, which is assumed to be the frustum of a cone with a characteristic angle of inclination with the pile–soil interface. A closed-form solution for the uplift capacity is obtained with no requirement of any charts or tables. Empirical relations using available literature are proposed for expressing critical embedment ratio and computation of net uplift capacity. The results are compared with a set of experimental data for 28 cases, ranging from loose to dense cohesionless soil up to maximum embedment ratio of 40, vis-a-vis available theoretical solutions. The proposed method leads to the predictions that are in good agreement with the experimental results. It further demonstrates the successful application of Kotter’s equation in the estimation of uplift capacity of pile anchors.

Plate Anchor Groups Pulled Vertically in Sand

Abstract: Results are presented of model-scale vertical pulling tests carried out on groups of square anchor plates in row and square configurations. The tests were carried out at a single depth of embedment, which ensured shallow anchor behavior in the sand placed at a constant dry density. It is shown that the load-displacement relationships for all groups may be reduced to a common curve. The load-carrying capacity of a group of anchor plates increases with the spacing between the individual plates up to a limiting critical value, and it is demonstrated how the results of pulling tests with different numbers of plates in a group may be described in a simple unifying manner. A possible means of predicting the effect of interaction on the uplift capacity of both modeland full-scale anchors in row configurations is suggested. For laboratory tests on a linear group of five anchors, it is shown that the end anchors attain the highest loads but all loads converge to an equal value as the spacing increases to the criti...

Nano-dynamic mechanical analysis (nano-DMA) of creep behavior of shales: Bakken case study

Abstract: Understanding the time-dependent mechanical behavior of rocks is important from various aspects and different scales such as predicting reservoir subsidence due to depletion or proppant embedment. Instead of using the conventional creep tests, nano-dynamic mechanical analysis (nano-DMA) was applied in this study to quantify the displacement and mechanical changes in shale samples over its creep time at a very fine scale. The results showed that the minerals with various mechanical properties exhibit different creep behavior. It was found that under the same constant load and time conditions, the creep displacement of hard minerals would be smaller than those that are softer. On the contrary, the changes in mechanical properties (storage modulus, loss modulus, complex modulus and hardness) of hard minerals are larger than soft minerals. The results from curve fitting showed that the changes in creep displacement, storage modulus, complex modulus and hardness over creep time follow a logarithmic function. We further analyzed the mechanical changes in every single phase during the creep time based on the deconvolution method to realize each phase’s response independently. Two distinct mechanical phases can be derived from the deconvolution histograms. As the creep time increases, the volume percentage of the hard mechanical phase decreases, while this shows an increase for soft phases. The results suggest that nano-DMA can be a strong advocate to study the creep behavior of rocks with complex mineralogy.