Engineering Commons^™

Piezoelectric Device For Measuring Shear Wave Velocity Of Soils And Evaluation Of Low And High Strain Shear Modulus, Saeed Ahmad

Electronic Thesis and Dissertation Repository

The shear wave velocity (V_s) and shear modulus (G) are important parameters that are required when dealing with a variety of geotechnical problems covering a wide range of shear strain in a soil medium. Different laboratory tests can be used to measure V_s and G such as resonant column, bender element and cyclic triaxial tests. However, these tests have several limitations in terms of stiffness of the test specimens and range of shear strain that can be applied to them. The importance of V_s in geotechnical engineering and the shortcomings of existing testing …

Investigation Of Hollow Bar Micropiles In Cohesive Soil, Osama F. El Hadi Drbe

Electronic Thesis and Dissertation Repository

Micropiles are used in various applications, including low capacity micropile networks, underpinning and seismic retrofitting of existing foundations and high capacity foundations for new structures. They facilitate fast installation with a high degree of ground improvement. The current Federal Highway Administration (FHWA) design guidelines designate hollow bar micropiles as Type B micropiles, even though their construction technique is different than typical Type B, which results in overly conservative design. In addition, the current practice for construction of hollow bar micropiles is limited to drilling bit/hollow bar diameter ratio of 2.5 or less. In this thesis, full-scale load tests were conducted …

Performance Of Hollow Bar Micropiles Under Axial And Lateral Loads In Cohesive Soils, Ahmed Yehia Abd El-Aziz

Electronic Thesis and Dissertation Repository

The use of hollow core bars in micropiles has greatly increased over the past ten years. Hollow core construction, also known as “self drilled”, is becoming a popular option because it allows a faster installation processes and ground improvement at the same time. Despite the growing demand for hollow bar micropiles, little work has been devoted to evaluating the nominal bond strength between the micropile grout and the surrounding soil, especially in clayey soils. Moreover, the performance of such micropiles under different kinds of loading is still largely unknown and needs to be investigated.

In this study, a research methodology …