Banca de DEFESA: PEDRO HENRIQUE DOS SANTOS SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PEDRO HENRIQUE DOS SANTOS SILVA
DATE: 18/09/2020
TIME: 14:00
LOCAL: Videoconferência
TITLE:

NUMERICAL ANALYSIS OF A SEMI-INTEGRAL BRIDGE ABUTMENT UNDERGOING CYCLIC LATERAL DISPLACEMENTS

KEY WORDS:

Semi-integral bridge. Bridge abutment. Soil-structure interaction. Numerical simulation. Cyclic loading.

PAGES: 112
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Integral abutment bridges (IABs) and semi-integral abutment bridges (SIABs) are structural systems built without thermal expansion joints at the abutments. In view of this peculiar characteristic, the abutment undergoes combined movements of translation and rotation due to expansion and contraction of the superstructure caused by temperature variations. Such behavior favors the increase of lateral earth pressures on the abutment and vertical displacements of the backfill surface, due to a complex soil-structure interaction mechanism associated with the cyclic lateral displacement of the abutment. The purpose of the present investigation is to assess the effects of cyclic lateral displacements on the response of the backfill-abutment system of a SIAB. A finite element model was developed and validated based on field data from an instrumented SIAB located in the State of Texas, USA. Field data were obtained from pressure cells installed against the abutment, and from temperature sensors positioned under the bridge superstructure. The soil stress-strain behavior was represented by a hyperbolic constitutive model, and the effects of expansion and contraction of the superstructure were given by prescribed horizontal displacements estimated from the temperature variations measured by the temperature sensors. Predictions with the proposed numerical model were found to produce a good match with the field data. After the validation phase, numerical simulations were performed to predict the daily and annual response of the backfill- abutment system, as well as to analyze the influence of the completion season of the bridge construction, the pile foundation stiffness, and the displacement magnitude on the response of the system. The lateral earth pressures on the abutment and the vertical displacements of the backfill surface increased with cycles. Earth pressures presented a nonlinear distribution along the abutment height. The largest settlements occurred near the backfill-abutment interface and decreased with increasing distance from the abutment. A heave was formed at a certain distance from the abutment. Earth pressures tended to reach a steady state after some cycles while vertical displacements were not found to stabilize. The completion season of the bridge construction influenced the vertical displacements but not the earth pressures. Earth pressures and vertical displacements were not affected by the pile foundation stiffness. The displacement magnitude influenced in both the earth pressures and the vertical displacements.

BANKING MEMBERS:
Presidente - 2551234 - YURI DANIEL JATOBA COSTA
Interna - 1524077 - CARINA MAIA LINS COSTA
Externo à Instituição - JORGE GABRIEL ZORNBERG - UT Austin
Externo à Instituição - JOSÉ ANTÔNIO SCHIAVON - ITA