Banca de DEFESA: Edwin Santos Colque

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Edwin Santos Colque
DATE: 25/11/2022
TIME: 14:00
LOCAL: Plataforma Microsoft Teams
TITLE:

STUDY OF THE DEFORMATIONS DEVELOPED IN SOFT SOILS DURING THE CONSTRUCTION OF TUNNELS WITH TBM-EPB

KEY WORDS:

Soft soil; Creep; Convergences; Parametric analysis; TBM-EPB; Plaxis 3D.

PAGES: 95
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SPECIALTY: Mecânicas dos Solos
SUMMARY:

With the growth of urban areas in terms of population and geography, underground structures are increasingly relevant to society. Recently, one of the largest urban tunnels in the world has been built in lacustrine soils, the Túnel Emisor Oriente (TEO), located in Mexico City. The difficult conditions on that soil required cutting-edge technology for excavating large tunnels, such as using the EPB-TBM technique. However, when measuring convergences in the support system during excavation, in some sections of the tunnel, relatively large values of vertical and horizontal convergences were measured, up to 17 and 14 cm, respectively. Within this context, as part of a collaboration project between the University of Brasilia (UnB) and the Institute for Engineering of the National Autonomous University of Mexico (UNAM), the present research aims to develop a three-dimensional parametric analysis to study the variables that influence the support system convergences and surface displacements when the tunnel is constructed with EPB-TBM technology in the lacustrine clays of Mexico City. The strength and deformation parameters of the lacustrine clay obtained from the CU and CD triaxial tests were validated and adjusted through the SoiltTest module of the Plaxis software, using the Soft Soil and Soft Soil Creep constitutive models, the latter considering the speed of load application. The finite element method (FEM, Plaxis 3D software) was used for the parametric analysis. From the analyses under undrained conditions, it was possible to determine that the convergences of the support system are influenced mainly by the face pressure, grout pressure and, mainly, the stiffness of the support system and the magnitude of the pore pressure drawdown. Considering drained conditions it was determined that the convergences of the support system are influenced mainly by the magnitude of the pore pressure drawdown and the considered construction time (creep), thus the maximum convergences measured in TEO were determined for pore pressure drawdown conditions of 70%, using the Soft Soil model, and of 40%, using the Soft Soil Creep model.

BANKING MEMBERS:
Presidente - 2161425 - JUAN FELIX RODRIGUEZ REBOLLEDO
Interno - 1805002 - ANDRE LUIS BRASIL CAVALCANTE
Interno - 404227 - MARCIO MUNIZ DE FARIAS
Externo à Instituição - GABRIEL AUVINET GUICHARD - UNAM