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MIT research areas
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5/22/2018 Research Areas of MIT
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Geotechnical Engineering, Geomechanics and Geotechnology back to top
ProfessorHerbert H. Einstein
Rock Fracture Characterization and Fracture Mechanics
Rock mass behavior, such as slope and tunnel stability and flow through rock is strongly affected by
fractures (joints). Fractured rock flow and related mechanisms are particularly important in energy
production, for example in unconventionals and engineered geothermal systems. This is a focal area for
the MIT-CEE rock mechanics group. The major emphasis is to examine how fractures propagate and
coalesce through lab experiments using high-speed observation, scanning electron microscope
observations and nano-identations and acoustic emissions. The experimental information is then used to
develop analytical models. Past research was sponsored by the National Science Foundation and the U.S.
Department of Energy. Present research also involves experiments and modeling of hydraulic fracturing
in the context of the Multiscale Shale Gas Collaborative sponsored by TOTAL-MITEI (see also research on
shales, below). For more information, visit the Video page for a short video showing some of this work.
ProfessorHerbert H. Einstein
Tunnel and other Infrastructure Design and Construction
Tunneling is one of the most expensive and uncertain civil engineering endeavors. It is, therefore,
essential to quantify and explicitly consider all factors that contribute to uncertainty in cost, time and
resources. Several major computer-based tools (Decision Aids for Tunneling, Decision Aids for Tunnel
Exploration) have already been developed and put to use to address uncertainty. Ongoing research
extends this work to complex tunnel systems and other heavy infrastructures to develop a procedure that
will make it possible to use experience gained from past projects, together with observations of a
particular project, to update predictions about construction cost and time as the tunnel or other
infrastructure is constructed.
ProfessorHerbert H. Einstein
Behavior of Shales
Shales, in the widest sense, are the most common near-surface rocks. Within the last decade, they have
become of great interest in conjunction with gas and oil extraction. Shales are also of great interest in civil
engineering because of their often problematic properties (low strength high deformability tendency
to swell). Professor Einsteins research in this area has been going on for 40 years, first related to civil
engineering problems and then resulted recently in models representing anisotropic behavior. The
present research is related to tight shales inconjunction with oil and gas extraction. In the context of
the project Multiscale Shale Gas Collaborative, sponsored by TOTAL-MITEI, propagation and
coalescence of fractures in shales are being investigated. This involves both experiments and modeling,
which can be based on previous research with other types of rocks. Very sophisticated testing procedures
and advanced models are being developed and used.
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ProfessorHerbert H. Einstein
Decision Analysis for EGS (Enhanced Geothermal Systems)
EGS rely on circulating water through rock fractures to extract heat and then through heat exchangers to
eventually produce electricity in addition to directly useable heat. In this context, holes need to be drilled,
artificial fractures created and the water circulation maintained through the lifetime of the system. Manyuncertainties affect this system, and this research addresses the uncertainties related to the subsurface
components. Specifically, stochastic fracture pattern models and fracture flow models are combined to
produce probabilistic flow models. In parallel, cost-time models for wells (drill holes) are developed.
Finally, on the basis of the fracture flow and drill cost/time models, models will be created to predict the
optimal location of the wells. The research is funded by the U.S. Department of Energy under the ARRA
(American Recovery and Reinvestment Act) Program.
ProfessorHerbert H. Einstein
Effect of Natural Hazards on Infrastructure Construction and Operation
Research on the physical aspects of landslides and associated hazard and risk analysis and decision
making processes has been conducted for many years. Recent extensions led to enhanced decision
making procedures involving, for instance, Bayesian networks and including the effect of conducting
exploration. The present work is a project in which the effect of natural hazards on the transportation
infrastructure construction and operation in Abu Dhabi is investigated. The processes and tools
developed in this context will be extended to other types of infrastructure and will form the basis for
similar approaches in other locations.
ProfessorJohn R. Williams
Pore Scale Simulation For Enhanced Oil Recovery
In an oil reservoir, 20-40% of the oil can be recovered by primary development techniques. The rest
remains trapped in the rock pores. Enhanced Oil Recovery (EOR) techniques, such as water flooding, gas
injection, chemical injection and thermal stimulation, optimistically recover an additional 10-20% of the
oil. This still leaves almost half of the oil trapped in the rock pores. The Department of Energy (DOE) has
estimated that if next generation EOR isapplied, the United States could generate an additional
240 billion barrels of recoverable oil resources - over 30 years supply at the present US consumption rate
of 20 million barrels per day. For comparison, the Middle East holds an estimated 685 billion barrels that
are recoverable and the tar sands of Alberta 300 billion recoverable barrels of heavy oil, with over a
trillion barrels potentially recoverable using enhanced methods. We are researching new EORtechnologies by providing understanding of the fundamental physical processes within a reservoir,
particularly at the pore scale. We are developing the computational algorithms for pore scale simulation of
oil reservoirs based on multi-scale, multi-physics models. The work leverages particle models based on a
partition of unity class of techniques, including SPH and DEM.
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ProfessorJohn R. Williams
Mutiscale, Multiphysics Simulation on Multicore Computers
A typical multiphysics simulation takes direct input from a microCT scan, at a resolution of some 8 billion
voxels of data. Each grain of rock has a different shape and may be cemented to other grains.
Furthermore, the surface properties of the grains influence the wetability of the rock/fluid system. Thegas, water and oil in the pores, and the rock matrix are then subject to driving forces, mainly mechanical
but also seismic, chemical and electrical. We have developed new algorithms to take advantage of shared
memory multicore computers. The challenge is to be fast but also to be thread safe. We have shown that
by tuning the task size to the hardware we can solve problems that were impossible even a few years ago.
ProfessorAndrew J. Whittle
Development of constitutive models for soils
Rate Effects in ClaysAlthough there are many observations of rate dependent properties of clays in laboratory element tests
there are no credible model formulations that consistently describe strain rate effects in shearing or creep
and relaxation in compression. The current research aims to develop and validate an elastic-viscoplastic
framework for clays that can extend prior elastoplastic models developed at MIT. The research makes
extensive use of unique experimental data on rate dependent undrained shear behavior and effects of
prior stress history. The goal is to develop a model that will resolve an enduring controversy (within the
geotechnical community) regarding the coupling of consolidation and creep (secondary compression),
and hence enable more reliable predictions of long-term ground movements for structures founded on
soft clay.
Multiscale Modeling of ClaysRecent advances in molecular modeling methods and nano-scale measurements of material properties
offer a new paradigm for understanding the multi-scale behavior of complex natural materials such as
clays. Recent studies at MIT have used molecular models to simulate the hydration of montmorillonite
and to predict elastic properties at different hydration states. We have also used molecular models to
investigate the interactions between clay platelets and hence, to develop the first meso-scale models of
clay aggregates. Future research will extend these analyses to include distributions of particle sizes and
different clay minerals. The long-term goal is to use the bottom-up approach to improve macroscopic
models of clay behavior.
Thermo-Hydro-Mechanical Behavior of ClaysThe coupling of thermo-hydro-mechanical properties of clays is of great importance in problems relating
to the containment of radioactive waste and ground source heat exchangers (shallow geothermal
heating/cooling systems). Research on the latter was initiated through a three-way collaboration with
colleagues at Tsinghua and Cambridge Universities. The MIT research aims to simulate ground response
due to seasonal heating and cooling using the TTS model formulated by colleagues at Tsinghua
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University. The TTS model is based on a novel thermodynamic framework where coupling between
thermal and mechanical properties is due to the exchange between bound and free water within the clay.
There are only limited data available to evaluate the model and future research will need to conduct more
extensive validation.
Ground Movements for Expansive Soil Subgrades Many parts of the continental US are underlain by expansive clays that undergo significant changes in
volume (swelling or shrinkage) due to seasonal changes in moisture content. Existing methods for
estimating these effects are based on simplified empirical procedures that are grossly overconservative. A
new research project aims to develop more reliable methods of analysis by simulating strains of partially
saturated clay due to seasonal changes in matric suction. The research will calibrate properties for a
complex elastoplastic model (BExM developed at UPC, Barcelona) based on a program of laboratory tests
on an expansive clay and to install a field station to monitor pore pressures and ground deformations at a
test site in Texas.
ProfessorAndrew J. Whittle
Analyses of Soil-Structure Interactions
Seismic Retrofit of Pile-Deck Wharf StructuresMany port facilities in the North America are vulnerable to severe damage in major seismic events. The
most critical structures are pile-supported wharf decks that are often founded within loose/uncompacted
fills. Lateral spreading (and potential liquefaction) of the fill slopes during an earthquake can cause
bending failure of the piles and collapse of the wharf. The main goal of this research is to investigate the
effectiveness of retrofit methods for improving seismic performance while causing minimal disruption of
port operations. Research on this topic was originally supported by NSF through a NEESR-Grand
Challenge project (led by colleagues at Georgia Tech.). The MIT research used the framework of OpenSees
to simulate the underlying (free-field) ground response that is then coupled to the structure through
macro-element representations of pile-soil interactions. Studies to date have shown the effectiveness of
PV drains as a method of mitigating structural damage for a broad suite of ground motions. On-going
studies aim to improve the modeling of cyclic response of the soils to enable more realistic predictions of
seismically induced slope failures.
Conductor-Soil InteractionThe oil spill resulting from the blowout of the Macondo Well and sinking of the Deepwater Horizondrilling ship has raised many critical questions regarding the safety of offshore drilling operations. A
multi-disciplinary research team at MIT is currently investigating possible failure mechanisms associated
with drilling rig drift-off or drive-off. These processes generate large loads and potential failure of the
conductor below the blowout preventer. Geotechnical research is focused on realistic analyses of the
conductor-soil interactions to simulate the large lateral deformations of the embedded conductor within
the soft marine clay sediments and subsequent dynamic response for riser separation. The analyses use
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constitutive models developed previously at MIT and are to be validated through comparisons with results
of physical model tests (carried out in a large geotechnical centrifuge facility at C-Core in St Johns) for
conditions typically found at deepwater sites in the Gulf of Mexico. The ultimate goal is to develop
simplified methods for representing conductor-soil interactions in simulations of the entire conductor-
riser system.
Ground Movements due to Soft Ground TunnelingThe prediction and mitigation of damage caused by construction-induced ground movements represents a
major factor in the design of tunnels. This is especially important for shallow tunnels in congested urban
environments, where expensive remedial measures such as compensation grouting or structural
underpinning must be considered prior to construction. The goal of this research is to develop and
evaluate new methods for predicting ground response due to tunneling. Research supported by Ferrovial-
Agroman simulates Earth Pressure Balance (EBP) tunnel boring machines in clay. The analyses consider
the role of face pressure, grouting around the precast lining rings and complex (non-linear and inelastic)
properties of the surrounding soil. Site-specific predictions have been compared with recent field
measurements during construction of Crossrail tunnels in London and with results of simplified analytical
models. Research is now focused on interactions of the tunnels with overlying buildings.
ProfessorAndrew J. Whittle
Monitoring & Control of Underground Infrastructure
Real Time Measurement and Modeling of Excavation Support SystemsThe designs of Temporary Earth Retaining Systems (TERS) for deep excavations are heavily regulated to
minimize risks during construction. The construction is then closely monitored to ensure conformance
with expected behavior and the performance is deemed acceptable while measurements remain below
pre-set trigger levels. While this paradigm ensures that TERS are safe and cause minimal damage, there is
little motivation to reduce the spiraling costs associated with overly conservative designs. This research
aims to integrate recent advances in computational analyses (massive 3D FE models) and in the design of
low cost wireless sensors, in order to develop a capability for real-time data interpretation and
prediction. This methodology will use the field monitoring data to update and re-evaluate model
predictions during construction and hence, offer a real-time observational framework that can reduce risk
while enabling more creative and cost effective designs of TERS. The current research is funded through
the Center for Environmental Sensing and Modeling and is being conducted in collaboration with the
Land Transport Authority in Singapore. The current involves applications for a series of subway station
projects under construction for the new Thomson Line. Next generation wireless strain gauges are being
designed and tested in collaboration with colleagues at Coventry University.
Monitoring and Control in Water Distribution NetworksMany cities worldwide must deal with the maintenance of aging infrastructures such as water distribution
systems where there are significant losses due to leakage, increasingly frequent failures due to pipe bursts
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and growing concerns regarding water quality in the pipe network. Prior research (WaterWiSe@sg)
funded through the Center for Environmental Sensing and Modeling, and carried out in collaboration
with the Singapore Public Utilities Board (PUB) has led to a proof-of-concept, end-to-end system for
continuous remote monitoring of the water distribution system in downtown Singapore (FCPH zone),
including a generic wireless sensing platform capable of measuring hydraulic (pressure and flow),acoustic (hydrophone) and water quality parameters (pH, ORP, conductivity, turbidity), a data collection
and visualization infrastructure, and a set of modeling and analysis tools. The testbed provides a unique
opportunity for advancing research capabilities. Current research includes the development of analytical
tools to 1) optimize the placement of sensors within the complex network, 2) improve the detection and
localization of hydraulic and water quality anomalies; and 3) automate tools that can enable sub-zones of
the system to be isolated (to reduce public health risks). Further studies aim to measure and characterize
the development of biofilms within the water pipes.