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Evaluation of tunneling technology using the Decision Aids for Tunneling
Abstract
It is desirable to evaluate new tunneling technologies before they are actually implemented. The Decision Aids for Tunneling (DAT) allow one to simulate tunnel construction and to study the effect of changes in tunneling technology. The effects on tunneling cost and time of potential changes in microtunneling and in tunneling with a full-face TBM have been investigated. After calibrating models of these methods using data from actual tunneling projects, various modifications were introduced, both individually and in combination. The study showed that improvements of individual aspects lead to maximum cost or time savings of 10% to 20%. Simultaneous improvements of several aspects can lead to cost and time savings up to 75%. In addition to these results, the study indicates that the DAT are powerful tools with which most effects on tunnel construction can be investigated.RésuméIl est souhaitable d'évaluer des innovations techniques en construction de tunnels avant de les appliquer. Les “instruments d'aide à la décision pour la construction de tunnels” (ADCT) permettent de simuler la construction d'un tunnel et d'étudier les effets de ces innovations. Dans cet article, nous avons examiné les effets de modifications techniques sur le coût et la durée de construction d'un tunnel construit soit par un microtunnelier soit par un tunnelier normal. Après une calibration des modèles représentants ces méthodes de construction avec des données provenant de projets actuels nous avons introduit plusieures innovations individuelles ou combinées. Cette étude montre que les améliorations individuelles ne permettent que des réductions de 10% à 20% des coûts ou des durées. Par contre, les améliorations qui combinent plusieures modifications réduisent les coûts et les temps jusqu'à 75%. On peut enfin ajouter que les ADCT sont des outils puissants avec lesquels la plupart des influences sur la construction de tunnels peuvent être examinées.
... Min et al. (2003Min et al. ( , 2008 used the DAT for a tunnel constructed by the drill & blast method. Analysis of the changes in tunneling technology effects' on time and cost for micro-tunneling and tunneling with a full-face tunnel boring machine (TBM) was facilitated via simulations using DAT (Sinfield and Einstein 1996). The DAT can also be Fig. 1 a Probabilistic ground-class profile along the tunnel route (Gi represents ground classes) b a time-cost scattergram (Reprinted from Einstein et al. (1996) with permission from ASCE) Geotech Geol Eng used for resource scheduling and planning as well as planning the handling of excavated material (Ritter et al. 2013;Min and Einstein 2016). ...
... This will facilitate more realistic modelling of the variability, as it usually is more tangible for the experts to assess the time of performing a unit activity (such as drilling, charging, etc.), than to try and assess directly the time of excavating a certain length of the tunnel. The DAT has the capability to break down any construction class into its unit activities (Sinfield and Einstein 1996). For the KTH model, Mohammadi et al. (2022) updated the application method to allow for such a breakdown into unit activities, while Isaksson and Stille (2005) originally assessed the production effort directly from a concept called production classes. ...
Time and cost estimation of tunneling projects is usually performed in a deterministic manner. However, because the deterministic approach is not capable of dealing with uncertainty, probabilistic methods have been developed over the years to better account for this problem. Three models of this type are the Decision Aids for Tunneling (DAT) and two models developed at KTH Royal Institute of Technology and the Czech Technical University in Prague. To conduct a probabilistic time and cost estimation, it is important to understand and account for not only the uncertain factors that affect the project time and cost but also the involved parties’ different interests and contractual responsibilities. This paper develops a risk model for the specific purpose of time and cost estimation of tunneling projects. In light of this model, the practical application of the three probabilistic models is discussed from a risk-aware decision-maker’s perspective. The acquired insights can be helpful in increasing the experts’ risk-awareness in modeling time and cost of tunneling projects.
... where Q is the index of the Q-system by Barton calculated considering the RQD 332 oriented along the tunnelling direction, SIGMA is the rock mass strength (MPa), F 333 is the average cutter load (ton), CLI is the cutter life index, q is the quartz content in 334 percentage terms, σθ is the induced biaxial stress on tunnel face (MPa). 335 The Q TBM value can be used for estimating TBM penetration rates and advance 336 rates for different rock conditions, both for prediction and for back analysis. First of all, the Authors defined a specific yielding criterion for the intact rock that considers the influence of petrographic and textural characters of the rock and 14 Variation of the strength of a rock specimen containing an inclined discontinuity. ...
... 325 The 'performance parameters'are recorded continuously from the data acquisition 326 system situated on the TBMs that systematically provides following parameters: 327 -Rotating speed of the head (round/minute) 328 -Instant advancing speed (m/h) 329 -Head penetration (mm/round) 330 -Head thrust (t) 331 -Absorbed power (kW) 332 -Excavated volume (m 3 ) 333 -Specific excavation energy (kWh/m 3 ) 334 The last parameter is obtained from the changes in the absorbed power and advancing 335 speed and it corresponds to the energy (or work) necessary to excavate rock volumes. 336 Therefore, it represents an index of the strength opposed by the rock mass to the 337 excavation. 338 A filter adjusted on the advancing intervals has to be used on the data gathered, are confronted with those of the head that must be detected topographically. ...
This chapter regards the geological risk management associated with the construction of underground works. Several methods either qualitative (matrix system, rock engineering system) or quantitative (safety methods) for risk analysis and risk evaluation are presented. In this chapter is also described an applicative example: the decision aids for tunnelling (DAT). This programme can simulate the realization of a tunnel starting from a geological profile constructed considering the statistical distributions of the possible uncertain parameters. The results can be used for a risk analysis of different scenarios or design modifications (exceeding certain times and/or costs).
... The Decision Aids for Tunneling (DAT) allow engineers to simulate tunnel construction considering uncertainties in geology and construction processes for a given tunnel and, as a result, obtain distributions of the total cost and duration of tunnel construction (Sinfield & Einstein, 1996). ...
... 2. Feedback from client. 3. Final simulation. ...
Applicability of the Decision Aids for Tunneling (DAT) technique is investigated in this study to better understand the efficiency
of the decision making process during tunnel construction. For this, a traffic tunnel under construction is adopted and information
on the construction procedure, i.e., overall geology, unit cost and construction time for each excavation process, is provided
periodically. Various scattergrams in which cost-time simulation results are plotted are obtained according to the simulation
methods and final prediction on the construction time/cost is made. It is found that the uncertainty in the cost distribution
is greater than the uncertainty in the time distribution foreach cycle simulation and the uncertainties in time and cost for theone time simulations are comparable. Future work will be concentrated on the updating scheme using the face mapping data and various
parametric studies will also be performed.
... The decision aids for tunneling (DAT) method was initially conceptualized in the 1980s by a research group at MIT University and has since undergone continual development (Sinfield and Einstein 1996). This methodology employs statistical and probabilistic techniques to forecast the geological conditions along the tunnel route, thereby enabling estimations of time and costs. ...
This study aimed to investigate and analyze the performance of twelve machine learning (ML) algorithms in estimating the construction time and cost of drill and blast tunnels. Thirteen tunnels located in different regions of Iran were selected, resulting in 900 data sets. Ten parameters were identified as influential factors affecting the construction time and cost of these tunnels. 80% of the data set was used for training, while the remaining 20% was reserved for testing. Additionally, 288 unseen data sets were utilized for evaluation purposes. All the algorithms demonstrated accurate performance on the test data sets, with R-squared values exceeding 0.93. However, only the Gaussian process regression algorithm achieved satisfactory results on the unseen data sets. Furthermore, a graphical user interface (GUI) was developed based on the trained ML models. This GUI allows real-time estimation of the time and cost of drill and blast tunnels and can be updated during construction.
... The safety assessment of shield tunnel construction needs to analyze many factors, especially the uncertainty problem. In the 1970s, HH Einstein first proposed the tunnel Risk management models, such as Geological Model for Tunnel Cost Model, Decision Aids in Tunneling [6], Risk and Risk Analysis in Rock Engineering [7]. After the shield tunnel project used the risk management concept, the related research developed rapidly. ...
... Sinfield and Einstein [6] noted the need for risk assessment before implementing new tunnel technologies, and they proposed the DAT (Decision Aids for Tunneling) method to simulate tunnel construction and study its effects. Social and economic risks and the optimization of economic risks are studied and applied to tunnels under construction in the Netherlands. ...
Constructing a shield tunnel that crosses under a river poses considerable safety risks, and risk assessment is essential for guaranteeing the safety of tunnel construction. This paper studies a risk assessment system for a shield tunnel crossing under a river. Risk identification is performed for the shield tunnel, and the risk factors and indicators are determined. The relationship between the two is determined preliminarily by numerical simulation, the numerical simulation results are verified by field measurements, and a sample set is established based on the numerical simulation results. Fuzzy comprehensive evaluation and a backpropagation neural network are then used to evaluate and analyze the risk level. Finally, the risk assessment system is used to evaluate the risk for Line 5 of the Hangzhou Metro in China. Based on the evaluation results, adjustments to the slurry strength, grouting pressure, and soil chamber pressure are proposed, and the risk is mitigated effectively.
... Thus, an early construction cost and time predicting tool for large-scale cavern construction is necessary to guide the decision makers during financial planning and construction budget estimation. The Decision Aids for Tunneling (DAT), developed by Einstein, Indermitte, Sinfield, Descoeudres, and Dudt (1999), has been used worldwide for underground construction projects as a decisionmaking tool (Chung, Mohamed, & AbouRizk, 2006;Min, 2003;Min, Kim, Lee, & Einstein, 2008;Sinfield & Einstein, 1996). It distinguishes itself from other risk assessment tools by allowing engineers to simulate the uncertainties in geology and construction methods involved in tunnel construction. ...
The applicability of the Decision Aids for Tunneling (DAT) as an early construction cost and time predicting tool for large-scale underground cavern construction projects is investigated in this study. For this purpose, three large-scale underground cavern construction projects in Singapore are presented using the proposed framework. The data from Project A, which is already completed, are used to validate the prediction outcomes. The results show that the proposed workflow can well estimate the construction cost and time at the 95% confidence level. The DAT simulation results of the other two projects, which are in the early planning stages, are compared with Project A to assess the accuracy of the predicted cost and time. The results show that the proposed workflow with the DAT as a predictor is a valuable tool in estimating construction cost and time for large-scale underground cavern projects, particularly for feasibility studies. Keywords: Cavern construction, Decision Aids for Tunneling, Partial face excavation, Construction cost-time prediction, Risk assessment, Feasibility study
... This early approach forms the basis for the Decision Aids for Tunneling (DAT). This simulationbased tool has been in ongoing development until the present time (Salazar and Einstein, 1986;Einstein et al., 1992;Sinfield and Einstein, 1996;Einstein et al., 1999;Einstein, 2004). The tool especially addresses uncertainties in geology and allows the consideration of probability distributions to model stochastic processes. ...
Production in mechanized tunneling frequently encounters disruptions due to sensitive process interdependencies. Reasons can be technical failures, insufficient capacity dimensioning, organizational deficiencies, or sensitive supply chains. These unproductive times could be reduced by an adequately designed project setup including logistical aspects. Therefore, possible disturbances must be identified and analyzed in detail. Based on this investigation, the machine and logistics setup can be changed to cope with unforeseen events. We present a modeling and simulation approach to analyze production and logistic processes of mechanized tunneling processes in a transparent and understandable way. The system is formalized in the modeling standard SysML. Thereby, we consider relevant system elements and process interdependencies to assess the effect of disturbances and to identify bottlenecks. We distinguish three kinds of disruptions: (i) technical failure of main elements related to the production processes, (ii) issues resulting from an insufficient supply chain, and (iii) cascading disturbances. The implementation in a simulation environment and the processing of relevant input data are presented hereupon. The presented approach is then illustrated by means of an application example based on a completed metro project. Three extending simulation studies quantify the impact of the identified disturbance categories.
... Simulation can be used to assess the advancement rate and find the problems of a project before it has started (AbouRizk et al. 1999;Nido et al. 1999). Though a few articles have been written concerning simulation and tunneling but most of these articles discuss the tunnel boring machine (TBM) method (Touran and Asai 1987;Sinfield and Einstein 1996;Touran 1997;Chung et al. 2006) used to build tunnel in soft rock. However, the Pakuashan highway tunnel located in central part of Taiwan is unique in soil condition and therefore, the New Austrian Tunneling Method (NATM) is the chosen method of excavation at the Pakuashan Tunnel. ...
Construction processes are complex operations that include the uses of equipment, materials, crews and geological conditions. Simulation can be used to study these processes in order to make competent decisions that will lower costs and shorten the duration of the project before it has started. Tunneling is a highly repetitive construction operation and simulation can be used to analyze the process. A model used to simulate the NATM tunneling construction operations for Pakuashan highway tunnel project is developed in this paper. This project is unique because of the soil conditions. A discrete event simulation methodology, CYCLONE, is used to build the operation model and simulate the tunneling processes. Statistical analysis indicates that duration of most tunneling operations can be modeled by Beta probability distribution. Results also show the model predicting the advancement rate of such tunneling project in accurate.
... Improvements could be expected in this respect by both increasing the amount of geotechnical investigations and making the best possible use of all available information. The development of decision aid systems, based on the statistical evaluation of geological data (Sinfield and Einstein, 1996) could assist the engineer in achieving a more accurate appreciation of construction hazards related to geological uncertainties. ...
Growing needs for modern transportation and utility networks have increased the demand for a more extensive and elaborate use of underground space. As a result, more underground projects have to be completed in a variety of ground conditions, including weak water bearing soils and soft rocks. Significant technological advances have rendered these projects possible, but have also given rise to new challenges as many of these projects have to be completed in difficult conditions, with very strict environmental constraints, particularly in urban areas where the potential impact of tunneling on existing structures is a major concern. This report addresses the main aspects of tunneling and underground works performed in soils and soft rocks. A summary is presented of the main features related to construction techniques, ground investigations, design methods, and instrumentation and monitoring practices, as well as of some of the more recent advances in these fields. Significant progress has been made in the area of soft ground tunneling over the past thirty years, partly because of advances in computer technologies. The scope of increasing difficult project conditions to be addressed requires that the best use be made of these technologies, as well as of lessons gained from past experience and current observational records.
... Even though the above issue has been investigated by many researchers, it still concerns the tunnelling society. Amongst other researchers, the efforts of Einstein [5][6][7] introducing the decision aids in tunnelling-DAT, should be noted. DAT simulates tunnel construction and studies the effects of different methods on the construction cost and time schedule. ...
Unexpected ground conditions have always been a major problem for the tunnelling industry. As demand for the development of new underground structures, regardless of the ground conditions, has increased, safety and risk considerations have become even more important. The methodology presented in this paper aims at the identification of risk-prone areas, incorporating, at the same time, the uncertainty of ground conditions. It is focused on TBM tunnelling and can be implemented in the early stages of the project. The methodology assesses the hazards by introducing the concept of a vulnerability index, which is based on the principles of rock engineering systems, to identify the weighting of the parameters, and on probabilistic modelling to address the uncertainty in the parameters’ values. The proposed model is illustrated via the Athens Metro case study, used also for validating its performance under actual construction conditions.
... In the majority of these research efforts, the main objective is to model the tunnelling process and make the performance assessment, based on the experience gained and the data gathered from past projects. However, even though probing risk conditions and identifying vulnerable areas that may disrupt the work progress have been incorporated in the models of many researchers (Einstein et al., 1992;Sinfield and Einstein, 1996), they have not yet been fully addressed, leaving room for further research. These problems are more intense in tunnelling projects constructed in complex geological formations (Barla and Pelizza, 2000) and especially in urban areas where the low construction depth and the external loading from the buildings increase risk conditions (Duddeck, 1996;Eisenstein, 1999). ...
Assessing TBM performance is an important parameter for the successful accomplishment of a tunnelling project. This paper presents an attempt to model the advance rate of tunnelling with respect to the geological and geotechnical site conditions. The model developed for this particular task is implemented through the use of an artificial neural network (ANN) that allows the identification and understanding of both the way and the extent that the involved parameters affect the tunnelling process. The model described in the paper is customised for the construction of an interstation section of the Athens metro tunnels, where the ANN generalisations provided precise estimations regarding the anticipated advance rate.
The Decision Aids for Tunneling (DAT) have been used world-wide in underground construction projects as a risk assessment tool. However, compared to the linear tunnel construction, underground cavern construction projects involve higher construction risks due to larger sizes and more complex tunnel networks. Therefore, it is useful to examine the capability of the DAT in simulating underground cavern construction with complex networks. This paper discusses the applicability of the modified DAT technique to real construction situation by considering a large scale underground cavern construction. The results show that the overall construction time obtained from the DAT analysis is comparable with the scheduled construction time proposed by the contractor. Time-cost scattergrams for the three partial face excavation scenarios are plotted and a final prediction on the construction time/cost is made. Finally, a parametric study is conducted by increasing the number of simultaneous cavern excavations in order to optimize the resource allocation on the construction site. The overall construction time was found to decrease exponentially with increase in number of simultaneous cavern excavations. The results show that the DAT is a valuable tool in predicting construction parameters and managing resources for underground cavern projects.
This paper discusses requirements to enhance the current decision-making process for tunnel construction, which involves significant uncertainties in ground conditions. In current practice, project managers determine resource-loaded construction schedules based on one specific set of ground conditions. In addition, they do not update ground conditions for unexcavated sections with information from excavated sections. This decision-making process often causes cost overruns, schedule delays, and disputes. To mitigate these problems, managers must make timely and robust decisions about construction schedules, during both the preconstruction and construction phases, in a transparent and integrated manner. To this end, we applied a 4D model-based decision-support system, the Development Strategy Simulator (DSS), to a U.S. tunnel project. Our analysis showed that the DSS was able to simultaneously analyze and represent the construction schedule and the resulting resources. However, we argue that it is still necessary to develop a progress-adaptive stochastic earth model, as well as a formal process for the automatic formulation and evaluation of multiple alternative schedules.
Construction simulation is the science of developing and experimenting with computer-based representations of construction systems to understand their underlying behavior. This branch of operations research applications in construction management has experienced significant academic growth over the past two decades. In this paper, the author summarizes his views on this topic as per his Peurifoy address, given in October 2008. The paper provides an overview of advancements in construction simulation theory as reported in literature. It then summarizes the key factors that contribute to successful deployment of simulation in the construction industry, and the key attributes of problems that make them more amenable for simulation modeling as opposed to other tools. The paper then provides an overview of long-term simulation initiatives leading to the next generation of computer modeling systems for construction, where simulation plays an integral role in a futuristic vision of automated project planning and control.
Tunneling's linearity causes planning complications: at any point, the actions that can be taken are determined by previous accomplishments. These constraints mean that tunneling projects require careful preparation for success. Current planning tools do not address the breadth and scope of the variables affecting tunneling and are not easily updatable. This paper contributes a real-world case study of the practical use of scenario-based simulation analysis for project planning and decision support in a CA$22 million utility tunneling project in Edmonton, Alberta, Canada. An integrated simulation-based solution for tunnel planning and decision support was created by using modular development and a high level architecture (HLA)-inspired communications framework. This is a demonstration of a generic yet flexible project modeling approach that may be of interest to both practitioners and researchers; it incorporates the modeling powers of simulation, appeals to a practicing tunneling engineer, and facilitates rapid scenario-based planning with swift development. The simulation was built in Simphony. NET and used to explore planning alternatives and for decision support during the project execution. DOI: 10.1061/(ASCE)CO.1943-7862.0000626. (C) 2013 American Society of Civil Engineers.
Tunnels projects are constructed to facilitate the execution of underground works with minor disturbance on surface structures and traffic. This is deemed important especially in downtown cities where disturbances should be minimized to assure flowability on surface and underground infrastructures. Microtunneling involves the use of a remotely controlled, guided pipe-jacking process in order to support excavation face. Microtunneling aids in avoiding the need of open trench for pipe laying, which causes extreme disruption to the surrounding. This paper presents a tool for planning microtunnels projects using computer simulation. The proposed tool aids contractors in planning microtunneling by estimating their associated time and cost of construction. There are six models that are coded in the proposed tool in order to capture the construction of microtunnels and shafts. The tool breaks down microtunnels projects into microtunnels segments and shafts which constitute several construction zones. An application example is presented to demonstrate the features of the proposed tool.
Tube tunnel systems for transporting freight in cities may provide an attractive solution to congestion problems. A feasibility study sponsored by the Federal Highway Administration examined the cost of building networks of tube tunnels with different network densities for a variety of freight sizes ranging from packets to standard containers. In this context, costs for tunneling, relocating utilities, and building access shafts in urban environments were determined. This paper briefly reviews the application of freight tube transportation systems. It concentrates on the cost data and the methodology by which the cost of tunneling networks is determined, since this information is of general interest and can be applied to similar projects. The cost calculated for a variety of tube network scenarios in actual city environments illustrates the applicability of the methodology and also indicates the potential viability of tube tunnel networks.
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 uncertainty about this part
of the tunnel will disappears. This new information can be used to update the geology of the tunnel in order to obtain more
precise prediction during construction. In this paper, the new study on the application of the DAT to update the geology of
the given tunnel is introduced. DAT simulation is updated based on face-mapping data and two approaches are used for the geologic
updating of the given tunnel. The results of simulations for the initial prediction and the updated prediction will be compared
in order to see how the construction time and cost distributions of the given tunnel are changed after the geologic updating.
Decision aids for tunneling (DAT), a computer-based tool, are used to determine tunnel construction cost and time as well as other information related to tunnel construction. Most important, the DAT allow uncertainties to be considered, an essential aspect in modern project and construction management. A brief overview of the DAT and of a variety of applications is first provided to (re)familiarize the reader. Emphasis is then placed on two recent DAT applications, namely, updating and resource management. Updating uses information collected during construction to reduce uncertainties. The resource management application shown here deals with reuse of muck to produce concrete. These practical cases reemphasize the wide variety of applications that can benefit from the use of the DAT.
Construction of a tunnel consists of many activities during the construction phase of the project, supporting is one of these activities. Immediate support elements are provided to control ground movement caused by stress redistribution during tunnel drive. Certain support elements are assembled in the excavated areas of crown, side wall and additionally on the tunnel face if necessary. Typical support elements are rock bolts, reinforced sprayed concrete, girders, etc. Loose ground and weak rock within the following rounds can also be supported using methods such as pipe umbrella, forepoling, earth wedge, etc. The Selection of efficient support methods for tunnelling is very important to reduce problems during construction and maintain project cost and time within the project budget and the planned schedule. This paper introduces a model that helps decision maker in selecting tunnel support methods in the conceptual phase of the project. The model calculates efficiency percentages of support methods based on project conditions. The model provides the user with a report including support methods and their efficiency percentages ranked in descending order.
The decision aids for tunneling (DAT) are a computer-based tool with which tunnel construction cost and time as well as required and produced resources can be computed. The DAT work with standard information such as geologic/geotechnical, structural, and material characteristics as well as construction performance. The two major components of the DAT, the "description of geology" and "construction simulation and construction management" are reviewed followed by descriptions of major applications of the DAT. Specifically, this involves application in the projects of two new transalpine rail tunnels in Switzerland (Gotthard, 57 km; Lotschberg, 36 km), investigation of different alternatives for a Metro project, and, finally, use of the DAT for assessing the effect of new tunneling technology on cost and time of construction.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1995. Includes bibliographical references (v. 2, leaves 209-210). by Vijaya Bhatta Halabe. Ph.D.
Decision Aids in Tunneling; Principle and Practical Application Monograph prepared for the Swiss Federal Office of Transportation
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