One of the most important issues in the calculation of the bearing capacity of rock masses is the method of application of the rock mass failure criterion. The Hoek-Brown failure criterion is the most useful criterion in practical applications. For applying this criterion in the upper bound method of limit analysis, one should linearize it using the single or multi-tangential technique. In this paper, the method of linearization of the Hoek-Brown criterion is investigated to determine the bearing capacity of embedded footings on rock masses. Since different stress levels have existed in the rock mass body, the multi-tangential technique results in the best approximation of the nonlinear Hoek-Brown criterion. As a novelty for the current research, the embedment depth of the footing is considered directly in the upper bound formulations instead of replacing it with an equivalent surcharge. The obtained results show that considering the embedment depth of footings along with using the multi-tangential technique result in increasing the accuracy of the results. In the methods which consider the embedment depth as an equivalent surcharge, the extension of the failure lines through the rock mass above the footing base cannot be considered.

With increase in cities' population and development of urbane life, passing buried pipelines near the ground's surface is inevitable in urban areas, roads, subways and highways. In this paper, the results of laboratory tests on exible pipe with a 160 mm diameter, placed in reinforced-trench by a geogrid layer and an EPS geofoam block subjected to repeated load are investigated. The pipe diameter change, strain and pressure acting over the pipe were measured throughout the loading, unloading and reloading. The parameters inspected in the tests included the thickness (30, 60 and 100 mm) and width (160 and 240 mm) of EPS block and burial depth of pipe (1. 2 and 1. 5 times the pipe diameter). Based on the results, the values of the pipe diameter change and pipe strain swiftly increases during the early cycles of loadings and followed the stability trend with the gathering of load cycles. In the geogrid-reinforced system, the change in pipe diameter and in pipe's strain at the end of the loading cycles showed 19% and 20% reduction, respectively, as related to the unreinforced system. According to the results, the minimum pipe diameter change and pipe's strain were acquired by using EPS block with maximum width, thickness, and 30 kg/m3 density over the pipe in addition to a geogrid layer representing values of, respectively, 0. 26 and 0. 3 times of the others acquired in the reinforced trench with a geogrid layer.

The behavior of the reinforced concrete structures is influenced by the bond-slip mechanism between concrete and rebar. The performance and strength of the structure are strongly affected by this mechanism. Therefore, it is indispensable to take bond-slip effects into account when analyzing reinforced concrete structures. In the current study, bond-slip behavior between concrete and reinforcement is investigated and a new bond-slip model for deformed bar is proposed. The main distinction between the proposed model and the current models is that in this model, slip starts when bond stress reaches a threshold value. Constant parameters of the proposed model are maximum bond stress and maximum slip. Calibration of the constant parameters of the model is done based on trial and error method with the aim of achieving the best coincidence with the experimental results. For each of constant parameters of the model, three different values were selected. So in total, nine models were used in modeling the interaction between rebar and concrete. To calibrate the model, some pull-out tests are simulated by finite element soft-ware of ABAQUS. In this simulation in order to take bond-slip effects into consideration, steel nodes are connected to that of adjacent concrete through non-linear springs. The behavior of these springs is defined based on a variety of bond-slip models for deformed bar. Considering the error of models with respect to experimental values, the best model with the minimum error was chosen. Moreover the best proposed model was compared with current models. The results showed that the proposed model has much better predictions than the current methods regarding both the maximum load and post-peak behavior of load deformation curve. Furthermore, the proposed model can be expanded for long bonded length and splitting failure mode by adding a reduction function for take into account post-yield strain effects.

In this study, the displacement finite element method was employed to evaluate the load-displacement response and estimate the ultimate pullout capacity of anchor plates. A detailed comparison was conducted between conventional and non-conventional shaped single-plate and multi-plate horizontal anchors. The analysis focused on square and plus-shaped anchors, examining the influence of anchor geometry, embedment depth, plate thickness, tie rod diameter, soil relative density, and spacing between plates on their pullout performance. The results indicated that pullout capacity increases with greater relative density, plate thickness, and embedment depth but decreases with larger tie rod diameters. Square anchors demonstrated 15–40% higher pullout capacities than plus-shaped anchors due to their larger contact area. Multi-plate configurations significantly improved pullout resistance compared to single plates, with critical plate spacing optimizing performance: 1.5b for square anchors and 1b for plus-shaped anchors. For dense sand, plus-shaped multi-plate anchors exhibited comparable pullout capacities to square single-plate anchors despite a 25% reduction in anchor area. At an embedment depth of 15 m, square triple-plate anchors achieved a pullout capacity of 360.6 MPa, while plus-shaped anchors reached 256.8 MPa. Stress distribution analysis revealed localized failure patterns above the anchors, with higher stress concentrations near the plates. These findings highlighted the effectiveness of multi-plate configurations and optimized geometries in improving anchor performance, offering practical solutions for geotechnical applications requiring high pullout resistance in sandy soils. Overall, plus-shaped double-plate and triple-plate anchors can effectively replace square-shaped single-plate anchors.

Offshore pipelines used for oil and gas transportation are often buried to avoid damage from fishing activities and to provide thermal insulation. Thermal expansion and contraction of the pipeline during operation can lead to lateral or upheaval buckling. A safe buried pipeline design must take into account a reliable evaluation of soil uplift resistance and pipe embedment depth. While the cost of burying a pipeline for tens or hundreds of kilometer is significant, it is important to optimize the required soil cover depth. In this paper a parametric study of pipeline upheaval buckling in clayey backfill has been conducted using finite element analysis. Three different embedment depths are considered. Uplift resistance is calculated and failure mechanism is obtained. To simulate the large penetration of the pipe into clayey backfill a novel Arbitrary Lagrangian Eulerian (ALE) finite element technique was employed in this paper. The results reveal that as embedment depth increases, uplift resistance increases and also uplift mechanism changes. However, uplift resistance differ less than 5% for deep embedment case. In addition, the amount of pore pressure is investigated beneath the pipe for deep embedment cases and it reveals that negative excess pore pressure occurs under the pipeline.

AbstractBackground: Reports of foreign bodies in oral tissues are available in the literature; however, this is the first report of complete embedment of a Stainless-Steel Crown (SSC) in the alveolar soft tissue.Case Report: Upon radiographic evaluation of a 19-year-old male patient seeking orthodontic treatment with several missing teeth, an SSC of the primary right mandibular second molar entirely encompassed by soft tissue was observed. The patient had no pain or discomfort in the region. The overlying mucosa had no sign of inflammation except for a slight pallor, and adjacent teeth had tilted into the space of the corresponding absent tooth. The crown was removed with a crestal incision under the local anesthesia.Conclusion: Infraocclusion of deciduous teeth, especially those covered with SSCs, should be strictly monitored clinically and radiographically as they can embed in soft tissue, cause severe bone defects, and complicate future treatments.

The purpose of this study was to introduce new wood engineered products and predict their strength in combination with the metal fasteners for timber structures construction. Investigation of steel dowel connections is an important issue that has attracted much attention today. There are many innovations in the constructions with the change in wood engineered products. For this research, a new combination of wood-based products was used; three layered structures consisted of birch plywood and OSB layers bonded by a single-component polyurethane resin in four configurations. The connections used in this study were steel dowels in 6 mm and 8 mm diameters. After producing new layered products, the embedment strength of samples was evaluated and compared to amounts calculated by engineering functions of resistance prediction according to EC5. Results showed that, the effect of the layered composition type as well as the steel dowel diameter was significant on the embedment strength of connection. Increasing of dowel diameter improved the embedment strength of materials. The compound with more contribution of plywood had higher embedment strength. The important point and purpose of this study was to evaluate the ability of EC5 in prediction of new engineered wood product strength, which revealed that the behavior of four material types could be predicted by EC5 with a sufficient accuracy and all material types had strength without failure occurrence and according to prediction.