Herbert H. Einstein

• Maheshwara Institute of Technology

We evaluate the radiated seismic energy normalized by external work for hydraulic fracturing, beam bending, and uniaxial compression experiments conducted on Opalinus clayshale and Barre granite specimens. Results suggest that normalized radiated seismic energy is highest for the beam bending, followed by uniaxial compression, and, finally, that th...

Core flood tests were conducted to study the effect of flow rate on the dissolution of the gypsum rock matrix and the formation of wormholes. An effluent chemistry monitoring system was designed and integrated into a triaxial system to provide continuous effluent concentration measurements, in addition to the pressure and flow measurements during t...

In the parallel paper by Li et al. (2019; https://doi.org/10.1029/2018JB017238), an effluent chemistry monitoring system was designed and used in core flood experiments to continuously measure the effluent concentration and study the evolution of the rock‐fluid system. In this study, the results from the parallel paper were used for interpretation...

Hydraulic fracturing is routinely used, but the fracturing processes that occur when rocks are hydraulically-fractured are not entirely understood and require further investigation. This study presents the acquisition, analysis and interpretation of acoustic emissions data from a series of laboratory hydraulic fracturing experiments on granite. Spe...

The authors discovered a mistake was made in the Mw calculations in this paper.

The dissolution of rocks in underground flow paths is transport-controlled if their dissolution rates are relatively high, while the dissolution is reaction-controlled if their dissolution rates are relatively low. Transport-controlled dissolution is a common process in the formation of gypsum karst and oil reservoir acid stimulations. As an initia...

The principal stress space has been traditionally used to describe and formulate isotropic strength criteria for materials, but it has limited functionality for anisotropic behavior, as it does not incorporate any information on material structure. In this paper we introduce a Normal Stress Space (NSS) comprising three normal stresses in the materi...

This paper interprets ground movements induced by tunnel construction, by comparing monitoring data with analytical and numerical predictions based on an assumed set of deformation parameters at the cavity boundary. By minimizing differences between the computed and measured ground movements, optimal cavity deformation parameters can then be used t...

High-speed rail (HSR) infrastructure is often built in areas prone to multiple hazards. In the planning stage, large areas and substantially different configurations can be considered, but appraising the solutions is a complex process. The value of each solution is affected by its layout, investment required, and performance under ordinary and extr...

When water flows through a preexisting cylindrical tube in gypsum rock, the nonuniform dissolution alters the tube into an enlarged tapered tube. A 2-D analytical model is developed to study the transport-controlled dissolution in an enlarged tapered tube, with explicit consideration of the tapered geometry and induced radial flow. The analytical m...

We present an experimental study in which a pre-notched specimen of Barre Granite was subjected to four point bending under crack mouth opening displacement control. The experimental observations consisted of load–displacement measurements, acoustic emissions, and photography on a macroscopic (~cm) as well as microscopic (~μm) scale. These observat...

In this paper, we describe approaches to risk determination in underground construction. The center piece of what we describe are the decision aids for tunneling (DAT), which allow one to predict cost-, time- and resource probability distributions reflecting uncertainties in geology and in the construction process but also many others. The DAT have...

Shales have undergone a complex burial diagenesis that involved a severe modification of the pore structure. Reconstituted shales can provide new insights into the nature of the pore structure in natural materials. The effects of diagenesis on the microfabric, pore size distribution, and porosity of Opalinus shale were measured by comparing the beh...

Understanding the cracking processes of rock is important regarding the fundamental material behavior and in engineering applications. Characterizing and predicting the cracking processes in shale is necessary when assessing unconventional oil and gas reservoirs and designing nuclear waste repositories. Of particular interest is the effect of beddi...

The paper presents methodologies for exploration planning under uncertain conditions based on virtual exploration and Bayesian updating. The process starts with site characterization using existing information to produce geologic profiles. Initial distributions of cost and time are obtained with a Bayesian network model that optimizes the construct...

This paper compares the microfabric characteristics of natural and reconstituted Opalinus clay shales. Reconstituted specimens are prepared using a resedimentation technique which enables the production of uniform specimens with replicable microstructures and engineering properties. The Authors investigated the evolution of porosity and microstruct...

Transportation construction projects are often plagued by cost overruns and delays. Applying contingencies and estimating risks at the project level often do not capture the multiple uncertainties in the construction process of large transportation projects. Thus, there is a need for innovative approaches and tools to avoid large construction cost...

Determination of the cracking levels during the crack propagation is one of the key challenges in the field of fracture mechanics of rocks. Acoustic emission (AE) is a technique that has been used to detect cracks as they occur across the specimen. Parametric analysis of AE signals and correlating these parameters (e.g., hits and energy) to stress–...

The selection of the macrolocation of new high-speed rail (HSR) systems during the planning stage affects the associated infrastructure costs. The process is influenced by the complex interaction between the HSR alignment, the technical solutions, and the characteristics of the deployment site, subject to layout restrictions. Decision support syste...

Resource scheduling and planning are the strategies required to determine the sequence of activities and resource allocation during tunnel construction. Resource scheduling and planning have been implemented in a new resource model of the Decision Aids for Tunneling (DAT), which are a computer based tool used to simulate tunnel construction. Tunnel...

Decisions in planning for transport infrastructure are the result of complex technical, political, and societal concerns. Its context of limited public funding and large costs require that decision making is soundly supported. When addressing real-world problems, however, it is extremely difficult to ascertain the system configuration yielding the...

An extensive network of urban and transportation systems is planned within the Abu Dhabi 2030 master plan. This includes planning, implementing and operating underground infrastructure for which it is extremely important to consider the uncertainties, and the inherent risks, affecting them. The research presented here intends to account for natural...

Z. Moradian, Q. B. Li, S. Morgan, B. Gonçalves da Silva J. T. Germaine, H. H. Einstein, (2015). Acoustic emission characteristics of shale. ISRM Congress 2015, Montreal, Canada,- ISBN: 978-1-926872-25-4

The Canadian Rock Mechanics Association (CARMA) and the American Rock Mechanics Association (ARMA) together with the leadership of the Congress under Professor Hassani organized a special ‘‘Shale Symposium’’ at the International Congress of the International Society for Rock Mechanics (ISRM). This symposium, which ran during four half days during t...

Swelling of clay-sulfate rocks often poses a severe threat in tunneling. It causes serious damage and produces high additional costs during tunnel construction and operation. The swelling of clay-sulfate rocks requires groundwater inflow into anhydrite-bearing layers. Therefore, the Darcy flux into anhydrite-bearing layers surrounding the tunnel is...

Hydrocarbon extraction is relying progressively more on hydraulic fracturing stimulation of shale. Enhanced Geothermal Systems (EGS) also rely on hydraulic fracturing to create fractures through which water is circulated to recover heat. While hydraulic fracturing has been extensively used in field applications, the fracturing processes involved in...

Gypsum (a mix of Hydrocal B-ll and Diatomaceous Earth) is used by the MIT rock mechanics group as a model rock material. Unconfined compression tests on pre-cracked specimens with high speed camera observation showed macro- cracking processes of gypsum similar to other materials; however in contrast to the other materials, no microcrack process zon...

Shale gas and oil production has grown rapidly in recent years, and consequently there are increasing demands to understand the mechanical and microseismic properties of shale. Acoustic emission (AE) monitoring provides useful information on the fracture mechanisms of shale rocks, and provides a basis for interpreting field seismic observations. Wh...

Wellbore drilling for any resource extraction—and particularly for EGS—is subject to many uncertainties, ranging from those related to geology to those related to the drilling procedures. Since well drilling and related subsurface activities for EGS represent a significant portion (above 50%) of the total EGS development cost, assessing the risk is...

In the last decades much effort has been devoted to the development of methodologies for landslide hazard and risk assessment. Although there are a few available glossaries, a review of the literature published in international journals and conferences show that the terminologies used differ greatly or are unclear. In 2011, the Joint Technical Comm...

Hydraulic fracturing is a method used routinely in oil and gas exploitation and in engineered geothermal systems. While used frequently, there are many aspects of hydraulic fracturing, such as the direction of propagation of the newly-created fractures, which are not very well understood. Even though it is known that the local stress field plays a...

Terrestrial laser scanning (TLS) can record a large amount of accurate topographical information with a high spatial accuracy over a relatively short period of time. These features suggest it is a useful tool for topographical survey and surface deformation detection. However, the use of TLS to survey a terrain surface is still challenging in the p...

This paper presents results from research conducted at MIT during 2010-2012 on modeling of natural rock fracture systems with the GEOFRAC three-dimensional stochastic model. Following a background summary of discrete fracture network models and a brief introduction of GEOFRAC, the paper provides a thorough description of the newly developed mathema...

Rather than submitting the complete paper at this time, an extended abstract is provided. The reason for doing so is that some relevant research is going on which should be included in the final paper. This paper will be made available to Congress participants both in form of a preprint and electronically.

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The classic experiment of a yielding trapdoor in (two-dimensional) plane strain beneath a granular mass is revisited, this time in the high-gravity environment of a geotechnical centrifuge. High-speed acquisition of load and displacement data makes it possible to examine the arching behavior of geomaterials. Results indicate the formation above the...

As all of our readers and authors know, there have been increasing problems with non-ethical behavior when publishing research. These problems range from not mentioning corresponding work by others, to publishing results that have not been sufficiently researched, to different degrees of plagiarism and fraud. So far, it appears that our journal has...

Hydrocarbon extraction from unconventional oil and gas reservoirs requires more accurate ways to describe fracture processes in shale. Fracture initiation, propagation and coalescence has been studied in many rock-like materials [1,2] and natural rocks [1,2,3]. However, shale is typically heterogeneous and anisotropic with naturally formed bedding...

The ambiguous nature of the factor of safety is first discussed in the context of a symmetric roof wedge of a circular tunnel, where two different definitions of the factor of safety are shown to be reconcilable when using the reliability index computed with the first-order reliability method (FORM). The probabilities of failure based on the second...

One of the most successful criteria proposed so far to describe the initiation and propagation of cracks under quasi-static loading in rock-like materials is a stress-based criterion developed by Bobet (Fracture coalescence in rock materials: experimental observations and numerical predictions. Sc. D, Thesis, Massachusetts Institute of Technology,...

The creation of numerical discrete element methods was a breakthrough in modeling discontinuous media and thus in modeling of rock masses. Recent developments in this domain, as also shown in a Special Issue of our Journal (Volume 45, Issue 5, September 2012), make it possible to simulate rock on any scale from intact rock composed of several parti...

This study explores the interaction between crack initiation and nanomechanical properties in the crack-tip fracture process zone of Carrara marble. Specimens with preexisting cracks were loaded in a uniaxial testing machine until the process zone appeared at the tips of the preexisting cracks. ESEM analysis reveals an increase in microcrack densit...

This paper presents a comprehensive study of the cracking and coalescence behavior of granite specimens with pre-existing flaw pairs. Uniaxial compressions tests were conducted on Barre granite with pre-existing flaw pairs of varying inclination angles $(\upbeta )$ , bridging angles $(\alpha )$ and ligament lengths (L). The cracking processes w...

A new automatic method for discontinuity traces mapping and sampling on a rock mass digital model is described in this work. The implemented procedure allows one to automatically identify discontinuity traces on a Digital Surface Model: traces are detected directly as surface breaklines, by means of maximum and minimum principal curvature values of...

This paper focuses on the analysis of the TBM performance recorded during the excavation of the Lötschberg Base Tunnel. The southern part of the tunnel was excavated by two gripper TBMs, partly through blocky rock masses at great depth. The jointed nature of the blocky rock mass posed serious problems concerning the stability of the excavation face...

Success in tunneling nowadays also depends on a sustainable tunnel design, which considers social, environmental, and economic issues. Planning the handling of excavated materials for a tunnel construction project will possibly avoid waste deposits, save mineral resources as well as energy, and reduce some of the project costs. Hence, planning the...

Large debris avalanches are characterized by extremely rapid, flow-like motion of large masses and they travel extremely long distances showing much greater mobility than could be predicted using frictional models. In order to investigate the mechanisms involved and the reasons for the large propagation of these phenomena a discrete element model (...

High-speed rail (HSR) networks require large investments, and the performance of the infrastructure is affected by varying local environments, while subject to tight layout restrictions. This paper presents a fully integrated three-dimensional model to optimize the HSR alignment at a planning scale, which sets boundaries for the final project desig...

An algorithm for determining the intersections between fractures is presented in this paper. The algorithm is implemented in GEOFRAC, a stochastic fracture pattern-modeling program. Previously, GEOFRAC allowed one to subdivide a fracture network into isolated subnetworks to assess connectivity. A new GEOFRAC feature can be used to analyze length an...

To counteract cost escalation and delays in infrastructure construction, an estimation model has been developed that simulates project uncertainty with probability distributions, correlations, and disruptive events. When applied to a new rail line project, three model inputs were not available from the designers: time distributions, cost correlatio...

The total construction cost and time of projects are often overrun. It is known that when positive correlations between costs are disregarded, the range of possible total construction costs is underestimated. A model is needed to estimate the effect of correlations on the probability distributions of total cost and total time. Four cost-cost and on...

The study of crack initiation and propagation is important for the understanding of rock mass behavior, which affects many rock engineering problems. Such studies can be done experimentally in the laboratory or in the field, or numerically. Here, a numerical study is presented, in which the stress and strain fields around a flaw tip were analyzed u...

This paper presents a methodology to systematically assess and manage the risks associated with tunnel construction. The methodology consists of combining a geologic prediction model that allows one to predict geology ahead of the tunnel construction, with a construction strategy decision model that allows one to choose amongst different constructi...

The fracture process zone (FPZ), a zone of weakened material surrounding the tip of a propagating crack, is common to many brittle materials, and is likely related to brittle material damage mechanisms. This study follows recent investigations of Carrara Marble and asks whether microstructure size, such as the size of marble grains, leads to an dif...

Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel excavation. The present study investigates the hydraulic effects of tunneling on groundwater flow and analyzes how hydraulic changes...

The validity of centrifuge modeling of soil systems is investigated by means of a "yielding trapdoor" setup similar to the one used by previous researchers for examining soil arching. A modeling-of-models exercise is thus carried out in accordance with centrifuge scaling requirements. This parametric study also includes the effects of g-level, grai...

In this study, an approach to estimate the swelling potential of clay-sulfate rocks in tunneling is presented. Swelling of clay-sulfate rocks leads to damage in tunnels that is difficult and costly to repair. Swelling is caused by the transformation of the sulfate mineral anhydrite into gypsum, which involves an increase in rock volume in a system...

Closed-form solutions are presented for a tunnel supported with Discretely Mechanically or Frictionally Coupled (DMFC) and with Continuously Mechanically Coupled (CMC) or Continuously Frictionally Coupled (CFC) rockbolts. The formulation is based on the following assumptions: (1) circular cross section; (2) deep tunnel; (3) Ko=1, i.e. axisymmetric...

This research study investigates the cracking processes associated with inclusion pairs of varying shape, orientation and inclusion materials. Specifically, this study summarizes a series of uniaxial compression tests on gypsum specimens with varying inclusion pair configurations. The inclusions consisted of differing materials, of contrasting Youn...

Presentation EGU 2011

This paper presents the results of an experimental investigation on the cracking behavior of brittle heterogeneous materials. Unconfined, uniaxial compression tests were conducted on prismatic gypsum specimens containing either one, or two, inclusions. These inclusions were of different strengths, stiffnesses shapes, and sizes. Emphasis was placed...

Rock slope instabilities are discussed in the context of decision making for risk assessment and management. Hence, the state of the slope and possible failure mechanism need to be defined first. This is done with geometrical and mechanical models for which recent developments are presented. This leads with appropriate consideration of uncertaintie...

This study explores the interaction between crack initiation and nanomechanical properties in the crack tip process zone (zone of microcracking at the tip of a propagating crack) of a brittle material. Samples of Carrara marble with pre-existing cracks ("flaws") were loaded in a uniaxial testing machine until the process zone appeared at the tips o...

Experimental uniaxial compression loading tests were conducted on molded gypsum and Carrara marble prismatic specimens to study the cracking and coalescence processes between pre-existing artificial flaws. The study showed that material had an influence on the cracking and coalescence processes (see the companion paper in this issue). As reported i...

Cracking and coalescence behavior has been studied experimentally with prismatic laboratory-molded gypsum and Carrara marble specimens containing two parallel pre-existing open flaws. This was done at both the macroscopic and the microscopic scales, and the results are presented in two separate papers. This paper (the first of two) summarizes the m...

The seismic stability of the Åknes rock slope, western Norway, was analysed by using the distinct element code UDEC (Universal Distinct Element Code). The slope poses a threat to the region as a sudden failure may cause a destructive tsunami in the fjord. The dynamic input was based on earthquakes with return periods of 100 and 1000 years, and in m...

This paper presents the use of a high speed video system (high speed camera) in studying the crack initiation, propagation, and coalescence in rocks. Prismatic laboratory-molded gypsum and Carrara marble specimens, which contained either a single artificial flaw or a pair of artificial flaws, were tested in uniaxial compression. The front face of t...

Experimental studies on fracture propagation and coalescence were conducted which together with previous tests by this group on gypsum and marble, provide information on fracturing. Specifically, different fracture geometries wsere tested, which together with the different material properties will provide the basis for analytical/numerical modeling...

Knowing the planar shape of discontinuities is important when characterizing discontinuities in a rock mass. However, the real discontinuity shape is rarely known, since the rock mass is usually inaccessible in three dimensions. Information on discontinuity shape is limited and often open to more than one interpretation. This paper discusses the pl...

This paper presents the results of an experimental study in which molded gypsum and Carrara Marble specimens containing a pre-existing flaw were tested in uniaxial compression. The main purpose of this study was to observe and characterize the cracks that emanate from a single pre-existing flaw. Seven different crack types were identified based on...

The unstable 650,000 m2 Åknes rock slope (Western Norway) poses a hazard, as a sudden failure may cause a destructive tsunami in the fjord. In this study the slope was divided into blocks based on displacements measured at the slope surface. Discontinuous deformation analysis (DDA) showed that three or four blocks in the upper half may be considere...

A data set was derived for the Åknes rock slope, Norway, with the main focus on deriving input parameters for the Barton–Bandis shear strength criterion. Back-calculations of a 100,000 m3 rock slide were performed for evaluation of the data set. The limit equilibrium analysis showed that the joint roughness coefficient (JRC) has the greatest effect...

Opalinus Clay shale, which is part of the mesozoic Dogger formation, underlies many parts of Northern and Western Switzerland. The rock has been encountered in many rail and road tunnels and it is also under consideration to be the host formation for a radioactive waste repository. This is a soft rock with relatively high deformability and medium t...

Numerous tunnels have been built and new tunnels are planned in Korea. As the demand for roads and railways increases, additional tunnels are needed because of the mountainous topography of Korea. This paper presents one such tunnel, the Sucheon tunnel, a road tunnel consisting of two parallel tubes approximately 1900m long. After a brief presentat...

Uniaxial compression tests were conducted on prismatic Barre Granite specimens with two pre-cut, straight, open flaws. Using a high-speed video system, crack initiation, propagation, and coalescence were observed. Coalescence patterns for the granite specimens fit into a previous framework (developed for Molded Gypsum and Carrara Marble) except for...

This research investigates the fracturing and coalescence behavior in prismatic laboratory-molded gypsum and Carrara marble specimens, which consist of either one or two pre-existing open flaws, under uniaxial compression. The tests are monitored by a high speed video system with a frame rate up to 24,000 frames/second. It allows one to precisely o...

Tunnel exploration is a classic problem of decision making under uncertainty. This paper, Part II, dealing with the exploration problem, discusses the sources of uncertainty in tunnel exploration, and provides techniques to formally incorporate uncertainties into the exploration planning. Part I described the state of uncertainty in geology and exp...

Exploration planning is a process of decision making under uncertainty. This paper, Part I of two dealing with the exploration problem, briefly reviews the decision analytical procedure for tunnel exploration, and provides practical techniques to do so. Specifically, this paper presents an approach by which the effect of additional exploration can...

This research formulates a Landslide Risk Rating System for the Greater Baguio area in the Philippines. It is hoped that the tool will be made a part of the physical/urban planning process when used by engineers and planners and used to address risks posed by landslides given the rapidly increasing concentration of population and the development of...

It has been observed in many tunneling projects that surface settlement troughs caused by twin tunnels have a variety of shapes unlike single tunnels, where symmetric surface settlement troughs are usually observed. The surface settlement troughs observed over twin tunnels can be symmetric with respect to the midpoint between the two tunnels or sym...

This paper is a somewhat revised version of the one previously given as a keynote lecture in the ECI Conference, ‘Geohazards: Technical, Economical and Social Consequences’. Some changes have been made to the original paper and the oral presentation: several of the figures and pictures illustrating the recent events have been eliminated, only one d...

Numerous empirical and analytical relations exist between shield tunnel characteristics and surface and subsurface deformation. Also, 2-D and 3-D numerical analyses have been applied to such tunneling problems. Similar but substantially fewer approaches have been developed for earth pressure balance (EPB) tunneling. In the Bangkok MRTA project, dat...

The use of a high speed video system allows one to precisely observe the cracking mechanisms, in particular if shear or tensile fracturing is taking place. The present experimental study on gypsum and marble specimens confirmed that tensile wing cracks (TWCs) are in most cases the first cracks to appear in fracture propagation from existing flaws i...

A total of 170 tests (68 tests for monotonic loading, 102 tests for cyclic loading) have been performed to investigate crack initiation, propagation and coalescence. The specimens have two pre-existing flaws which are arranged at different distances and angles. Wing cracks and secondary cracks are observed in both monotonic and cyclic tests. Wing c...

Fractures govern flow, deformation and strength of rock masses. Fracture flow is important with regard to resource extraction (water, gas, oil) as well as groundwater contamination. Fractures through their effect on deformability and strength govern stability of tunnels and slopes in rock and the behavior of building,-, bridge - and dam foundations...

Fractures govern flow, deformation and strength of rock masses. Fracture flow is important with regard to resource extraction (water, gas, oil) as well as groundwater contamination. Fractures through their effect on deformability and strength govern stability of tunnels and slopes in rock and the behavior of building,-, bridge - and darn foundation...

The Decision Aids for Tunneling (DAT) is a computer based tool with which one can obtain distributions of the tunnel constructin cost and time considering uncertainties of the geology and construction process for a given tunnel. As construction progresses, geologic information is checked based on the excavated part of the tunnel and, therefore, the...