Embedment

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

Bond-Slip Analytical Formulation toward Optimal Embedment of Concrete-Filled Circular FRP Tubes into Concrete Footings

Abstract: This paper presents a robust analytical model for a moment connection of concrete-filled fiber reinforced-polymer (FRP) tubes (CFFTs) to concrete footings. The CFFT connection is based on a simple approach of direct embedment into the footing, thereby eliminating the need for connection rebar or mechanical devices. The CFFT is externally subjected to lateral and axial loads, resembling practical applications such as piles affixed to pile caps, bridge columns, or utility poles. The model adopts the concepts of equilibrium, deformations compatibility, and nonlinear concrete stress-strain behavior. It also employs a “bond stress-slip” relation that can be obtained from simple push-through tests on some of the commercially used tubes. The model can predict the critical embedment length Xcr , which is the minimum length required to achieve material failure of the CFFT outside the footing, and bond failure inside the footing, simultaneously. If the actual embedment length is less than Xcr , bond failure occurs ...

Analytical Seismic Assessment of a Tall Long-Span Curved Reinforced-Concrete Bridge. Part I: Numerical Modeling and Input Excitation

Abstract: The seismic response of bridges is affected by a number of modeling considerations, such as pier embedment, buried pile caps, seat-type abutments, pounding, bond slip and architecturally flared part of piers, and loading considerations, such as non-uniform ground excitations and orientation of ground motion components, which are not readily addressed by design codes. This article addresses a methodology for the nonlinear static and dynamic analysis of a tall, long-span, curved, reinforced-concrete bridge, the Mogollon Rim Viaduct. Various modeling scenarios are considered for the bridge components, soil-structure interaction system, and materials, i.e., concrete and reinforcing steel, covering all its geotechnical and structural aspects based on recent advances in bridge engineering. Various analysis methodologies (nonlinear static pushover, time history response to uniform and spatially variable seismic excitations, and incremental dynamic analyses) are performed. For the dynamic analyses, a suite of nin...

Bearing capacity of semi-deep skirted foundations on clay using stress characteristics and finite element analyses

Abstract: Semi-deep skirted foundations are now considered to be a viable foundation option for a variety of onshore and offshore applications. The capacity under combined vertical, horizontal, and moment loadings must be found to ensure their capability and stability. In this study, undrained bearing capacity subjected to vertical loading, as part of combined loading is determined through stress characteristics and finite element analyses. Circular skirted foundations with different soil strength and geometries considering embedment depth effects have been studied. Stress field, kinematic mechanism accompanying failure, and bearing capacity factors for various embedment ratios are investigated. Acquired vertical failure mechanism has demonstrated the transition from a general shear to a punch shear failure. Comparisons with different research works including conventional methods, upper and lower bound, finite element analyses, physical modeling, experimental, and centrifuge tests have indicated the underes...

Moment Connection of Concrete-Filled Fiber Reinforced Polymer Tubes by Direct Embedment into Footings

Abstract: A moment connection of concrete-filled fibre reinforced polymer (FRP) tubes (CFFTs) to concrete footing is explored. The CFFTs are directly embedded into the footings to develop their full moment capacity, in lieu of using mechanical connections, dowel reinforcing bars, or posttensioning methods. CFFT specimens of 219 mm diameter (D) were embedded into footings, at various depths, ranging from 0.3D to 1.5D. The CFFT cantilevered specimens were then laterally loaded to failure. The objective was to establish the critical embedment length, which was found to be 0.73D. Shorter embedment lengths resulted in a bond failure associated with excessive slip, where the full flexural strength of CFFTs was not reached. Specimens with the critical or longer embedment lengths have achieved flexural tension failure of the CFFT, just outside the footing. Ancillary push-through tests were also carried out using CFFT stubs embedded into concrete footings, throughout the full thickness of the footing, and tested under conce...

Effect of boundary conditions on buckling of friction piles

Abstract: In practice, evidence suggests that long, slender piles subjected to axial loads can fail under axial stresses below the yield point of the pile material. A general solution for critical buckling capacity of long, slender friction piles in clay is presented using the minimum potential energy method. The Rayleigh-Ritz method is adopted to select deflection functions satisfying six geometric boundary conditions encountered in practice. Parameter studies were performed to investigate the buckling response of fully and partially embedded piles and the effect of pile-top and tip conditions on buckling capacity. Results indicated that the boundary conditions at the pile tip have no effect on the critical buckling capacity in cases in which the nondimensional embedment length (\Ih\N’) exceeded a critical value. In addition, for fully embedded piles, the effect of embedment length was nearly negligible after \Ih\N’ exceeded a value of 6 for fixed-with-sway pile-top conditions.