Seminars

Neural Networks in Scientific Computing
Daniel M. Tartakovsky

 Neural networks (NNs) have become ubiquitous in scientific computing, including qualitative predictions of subsurface phenomena. Yet, the question of what they are good for remains unresolved. We discuss several where NNs might offer advantages over the existing alternatives. One is the use of NNs as surrogates or emulators of partial differential equations (PDEs) that describe the dynamics of complex systems. A virtually negligible computational cost of such surrogates renders them an attractive tool for ensemble-based computation, which requires a large number of repeated PDE solves.

Data-driven Solid Mechanics for Big and Small Data
Steve WaiChing Sun

We present an adaptive hybridized model-based/model-free strategy that ensures the feasibility of multi-physics simulations when different amounts of data are available.  In the data-rich situation, we extend the data-driven approach where the hydraulic and solid constitutive laws may switch from model-free to mode-based depending on the availability of data. Techniques related to identifying the constitutive manifold, the influence of the normed space, and the distance-minimized algorithm accelerated by the K-dimensional tree search will be discussed.

Non-Invasive Subsurface Site Characterization for Seismic Ground Response Analyses
Professor Brady R. Cox, Ph.D., P.E.

Numerical earthquake wave propagation simulations, known as ground response analyses (GRAs), are commonly performed in an attempt to estimate the site-specific, frequency-dependent amplification of seismic waves (i.e., site effects) as they travel from a reference bedrock condition up through soil layers to the ground surface. The importance of accurately predicting site effects for engineering infrastructure projects in seismically active regions cannot be overstated.

Application of Particulate Models to Problems in Energy Geotechnics
T. Matthew Evans

A diverse array of (broadly defined) energy applications is an increasingly large part of the geotechnical engineer’s portfolio, both in research and practice.

“Understanding the Use of Bentonite as a Buffer Material for the Geological Disposal of High-Level Radioactive Waste: Experiments and Numerical Modeling
LianGe Zheng

Disposal of high-level radioactive waste in geologic repositories involves a multi-barrier system that comprises of an engineered barrier system (EBS) and the host rock (or natural barrier system). One of the common components of the EBS is a bentonite buffer material which has several beneficial features such as a low permeability as well as a high swelling and retardation capacity. Bentonite is a very complex geo-material: it is composed of swelling clay minerals (i.e.

FRP-Confined RC Columns with Transverse Steel Confinement: From Finite Element Modeling to Reliability-Based Calibration of Design Equations
Michele Barbato, Ph.D

External confinement of reinforced concrete (RC) columns with fiber-reinforced polymer (FRP) wraps is a technique extensively used for strengthening and retrofit of structurally deficient columns. Due to modern design codes’ requirements, new RC columns tend to have higher amounts of both longitudinal and transverse steel when compared to older columns.

Sequential Excavation Method (SEM) for the San Diego Courthouse Commons Tunnel Project
Tom Pennington, PE, P.Eng, M. ASCE

This seminar will present the recent application of Sequential Excavation Method (SEM) tunneling techniques used for construction of the Courthouse Commons (COCO) Tunnel in downtown San Diego. The COCO Tunnel is a component of the larger Courthouse Commons Development Project and involved construction of a 300-foot long, 28-foot diameter tunnel located directly beneath an existing multi-story building.

Sequential Excavation Method (SEM) for the San Diego Courthouse Commons Tunnel Project
Tom Pennington, PE, P.Eng, M. ASCE

This seminar will present the recent application of Sequential Excavation Method (SEM) tunneling techniques used for construction of the Courthouse Commons (COCO) Tunnel in downtown San Diego. The COCO Tunnel is a component of the larger Courthouse Commons Development Project and involved construction of a 300-foot long, 28-foot diameter tunnel located directly beneath an existing multi-story building.

Safety and Certification of Discontinuous Fiber Composites (DFCs) For Aerospace Applications: Design, Testing, and Computational Modeling
Marco Salviato, PhD

Composite materials are finding increasing use across the most important industrial sectors including e.g. aerospace, automotive, and wind energy. This is owed to their excellent specific mechanical properties and their taylorability paving new avenues for structural optimization and weight savings. Engineering marvels such as the Boeing 787 have already proven the benefits of composites and showed that it is possible to adopt these materials in the commercial sector.

Understanding Seismic Retrofit, Adaptive Reuse and Rehabilitation of Existing Buildings
Matt Skokan, Ph.D., S.E. & Robert Randall, S.E.

This seminar will provide an overall understanding of seismic retrofit and adaptive reuse of existing buildings.  Topics covered will include a discussion of the following: