Prior to 2012,the integration of designed vertical or horizontal curves into microtunnel alignments was unheard of in Ontario.Straight and relatively short microtunnels,less than 200m long,were the local accepted indu...Prior to 2012,the integration of designed vertical or horizontal curves into microtunnel alignments was unheard of in Ontario.Straight and relatively short microtunnels,less than 200m long,were the local accepted industry standard.Following the release of a large number of infrastructure projects in the suburban Greater Toronto Area(GTA),clients and design consultants encouraged contractors to present value engineered alternatives to proposed project alignments and construction methods.Such an initiative has allowed contractors to develop cost effective solutions,which harnessed the application of state-of-the-art microtunnelling methods and equipment.As a result,several recent projects now feature pre-designed curved microtunnels as part of the tender documents.This paper discusses,in technical detail,three recent projects,whereby,long distance curved microtunnels were successfully constructed.Each of the projects had tunnel drives exceeding 300m in length,ranging in diameter from 1200mm ID to 1500mm ID,incorporating the use of Vertical,Horizontal,and Spatial Curves.Critical parameters such as pre-project planning and engineering are highlighted,while the importance of post-tunnelling assessments is also discussed.展开更多
Microtunnelling operations do not reach the highest possible productivity due to influences by different soil compositions.Hence, there is a need for a better understanding of the construction process and of those fac...Microtunnelling operations do not reach the highest possible productivity due to influences by different soil compositions.Hence, there is a need for a better understanding of the construction process and of those factors influencing productivity. Theefficiency ofMTBM （microtunnel boring machine） will be increased by that knowledge. In the paper, a flexible simulation module isdeveloped. It helps to analyze the processes and to identify the influence of different soil compositions on the productivity ofmicrotunnelling operations. In view of these objectives, a model describing the microtunnelling process for an actual project at thecity of Recklinghausen, Germany is created by using CYCLONE methodology. Subsequently, the WebCYCLONE is applied toexecute the CYCLONE model in order to get the results. It helps to analyze and identify the influence of different soil compositionson the productivity of tunnel construction with microtunnelling in the job-site.展开更多
The popularity of trenchless techniques as a means of utility pipeline installation in urban environments,specifically microtunnelling/pipe-jacking,has increased in recent years due to its minimally-disruptive nature ...The popularity of trenchless techniques as a means of utility pipeline installation in urban environments,specifically microtunnelling/pipe-jacking,has increased in recent years due to its minimally-disruptive nature and reduced carbon footprint in comparison to conventional open-cut excavation methods.The response of pipes during the jacking process is complex and is governed by several factors,including ground conditions,the amount and distribution of lubrication,pipe and annulus size,pipeline misalignments and jacking force eccentricity,among others.Design practice remains based on empirical equations and previous drives through similar geology,resulting in uncertainty in jacking force estimates,thereby restricting adoption of the technique.In order to improve our understanding of the pipe-jacking process,pipes incorporating sensors providing real-time measurements of earth pressures,pore water pressures,axial strains and hoop strains can be used;but the number of such studies reported in the literature is small and the potential of instrumentation on routine projects is largely untapped.Moreover,jacking pipe monitoring practice lags behind the state-of-the-art instrumentation techniques used for monitoring other geotechnical infrastructure.The purpose of this paper is to provide a thorough review of learnings from instrumented pipe-jacking case studies and other supporting research,as well as to propose potential solutions to research gaps in the current state of design practice and field monitoring of pipe jacking projects.展开更多
This paper provides a review of the history and development of pipe jacking and microtunneling methods with extensive referencing to the published literature.The application of such methods in comparison with other tr...This paper provides a review of the history and development of pipe jacking and microtunneling methods with extensive referencing to the published literature.The application of such methods in comparison with other trenchless technologies is discussed and the various planning,design and construction aspects are introduced.The emphasis of the paper is to trace the academic research and field monitoring results covering critical aspects of design and construction with a particular emphasis on jacking force estimation and the effect of lubrication on jacking forces.展开更多
So many potential risks can be identifed for application of trenchless technology especially using microtunneling methods.Unexpected changes in ground conditions,such as encountering boulders,tree roots,ground water a...So many potential risks can be identifed for application of trenchless technology especially using microtunneling methods.Unexpected changes in ground conditions,such as encountering boulders,tree roots,ground water and man-made structures such as old foundations are the principal geotechnical risks,which affect the selection of an appropriate microtunnel boring machine.On the other hand,the performance of each microtunneling technique will differ while encountering such conditions.Hence,predicting the potential hazards provides a better safety and risk management plan.In this study,a couple of potentially hazardous situation,which are commonly associated with ground conditions,were identifed and investigated.A decision tree aid methodology was proposed based on geotechnical risk assessment for selection of proper microtunneling technique.Based on the approach the most appropriate microtunneling technique has the minimum risk level either before or after hazards mitigation measures.In order to check the effciency of the approach in practice,selection of microtunnel boring machine for Hamadan sewerage pipeline project was evaluated.Accordingly,an earth pressure balance(EPB)MTBM was selected for the project.展开更多
The subsurface space in urban areas is an important asset.However,the information available on this environment is relatively poor compared to above ground information.This paper proposes a Building Information Model(...The subsurface space in urban areas is an important asset.However,the information available on this environment is relatively poor compared to above ground information.This paper proposes a Building Information Model(BIM)for underground applications as means to address this information gap.The creation and progressive update of BIM for a constructed artefact ensures that data on the structures is available and can be used throughout its lifetime.A BIM for underground applications integrates data on surface structures,such as buildings,and subsurface infrastructures,such as pipes,along with details of the surrounding ground,the associated soil and rock properties and groundwater regime into a single framework.This approach is demonstrated by applying it to trenchless construction operations,including a microtunnelling project for a new sewer.The data from this extended BIM concept can be interactively used with analysis packages to conduct risk assessments for new construction activities.It also shows how BIM for the Underground can be used throughout the planning,construction and post-construction stages of a project,and,importantly,how this information can be available for future projects.展开更多
In recent years,there has been an increased resort to microtunnelling/pipe-jacking as a means of constructing underground conduits(for water,sewage,gas,and other utilities)to avoid on-street disruption in urban areas....In recent years,there has been an increased resort to microtunnelling/pipe-jacking as a means of constructing underground conduits(for water,sewage,gas,and other utilities)to avoid on-street disruption in urban areas.In this paper,technical details of two 1200 mm internal diameter microtunnels in silty sand totalling over 550 m in length are discussed.While average skin friction values are extremely low for both drives suggesting effective lubrication practice,differences in normalised bentonite volumes appear to be responsible for differences in skin friction.Full or near full buoyancy of the pipeline has been demonstrated for the majority of the drive.The frictional stress increase after a stoppage is shown to depend on not only the stoppage duration but also on the normalised lubrication volume.Interpretation of data in the manner presented in the paper is an important means of assimilating experience of microtunnelling in different ground conditions.展开更多
文摘Prior to 2012,the integration of designed vertical or horizontal curves into microtunnel alignments was unheard of in Ontario.Straight and relatively short microtunnels,less than 200m long,were the local accepted industry standard.Following the release of a large number of infrastructure projects in the suburban Greater Toronto Area(GTA),clients and design consultants encouraged contractors to present value engineered alternatives to proposed project alignments and construction methods.Such an initiative has allowed contractors to develop cost effective solutions,which harnessed the application of state-of-the-art microtunnelling methods and equipment.As a result,several recent projects now feature pre-designed curved microtunnels as part of the tender documents.This paper discusses,in technical detail,three recent projects,whereby,long distance curved microtunnels were successfully constructed.Each of the projects had tunnel drives exceeding 300m in length,ranging in diameter from 1200mm ID to 1500mm ID,incorporating the use of Vertical,Horizontal,and Spatial Curves.Critical parameters such as pre-project planning and engineering are highlighted,while the importance of post-tunnelling assessments is also discussed.
文摘Microtunnelling operations do not reach the highest possible productivity due to influences by different soil compositions.Hence, there is a need for a better understanding of the construction process and of those factors influencing productivity. Theefficiency ofMTBM （microtunnel boring machine） will be increased by that knowledge. In the paper, a flexible simulation module isdeveloped. It helps to analyze the processes and to identify the influence of different soil compositions on the productivity ofmicrotunnelling operations. In view of these objectives, a model describing the microtunnelling process for an actual project at thecity of Recklinghausen, Germany is created by using CYCLONE methodology. Subsequently, the WebCYCLONE is applied toexecute the CYCLONE model in order to get the results. It helps to analyze and identify the influence of different soil compositionson the productivity of tunnel construction with microtunnelling in the job-site.
基金funded by the Science Foundation Ireland Research Centre in Applied Geosciences(SFI-iCRAG),with Ward and Burke Construction Limited as the industry partner.
文摘The popularity of trenchless techniques as a means of utility pipeline installation in urban environments,specifically microtunnelling/pipe-jacking,has increased in recent years due to its minimally-disruptive nature and reduced carbon footprint in comparison to conventional open-cut excavation methods.The response of pipes during the jacking process is complex and is governed by several factors,including ground conditions,the amount and distribution of lubrication,pipe and annulus size,pipeline misalignments and jacking force eccentricity,among others.Design practice remains based on empirical equations and previous drives through similar geology,resulting in uncertainty in jacking force estimates,thereby restricting adoption of the technique.In order to improve our understanding of the pipe-jacking process,pipes incorporating sensors providing real-time measurements of earth pressures,pore water pressures,axial strains and hoop strains can be used;but the number of such studies reported in the literature is small and the potential of instrumentation on routine projects is largely untapped.Moreover,jacking pipe monitoring practice lags behind the state-of-the-art instrumentation techniques used for monitoring other geotechnical infrastructure.The purpose of this paper is to provide a thorough review of learnings from instrumented pipe-jacking case studies and other supporting research,as well as to propose potential solutions to research gaps in the current state of design practice and field monitoring of pipe jacking projects.
文摘This paper provides a review of the history and development of pipe jacking and microtunneling methods with extensive referencing to the published literature.The application of such methods in comparison with other trenchless technologies is discussed and the various planning,design and construction aspects are introduced.The emphasis of the paper is to trace the academic research and field monitoring results covering critical aspects of design and construction with a particular emphasis on jacking force estimation and the effect of lubrication on jacking forces.
文摘So many potential risks can be identifed for application of trenchless technology especially using microtunneling methods.Unexpected changes in ground conditions,such as encountering boulders,tree roots,ground water and man-made structures such as old foundations are the principal geotechnical risks,which affect the selection of an appropriate microtunnel boring machine.On the other hand,the performance of each microtunneling technique will differ while encountering such conditions.Hence,predicting the potential hazards provides a better safety and risk management plan.In this study,a couple of potentially hazardous situation,which are commonly associated with ground conditions,were identifed and investigated.A decision tree aid methodology was proposed based on geotechnical risk assessment for selection of proper microtunneling technique.Based on the approach the most appropriate microtunneling technique has the minimum risk level either before or after hazards mitigation measures.In order to check the effciency of the approach in practice,selection of microtunnel boring machine for Hamadan sewerage pipeline project was evaluated.Accordingly,an earth pressure balance(EPB)MTBM was selected for the project.
基金The authors gratefully acknowledge the financial support of EPSRC to Stylianos Providakis to enable him to undertake his doctoral studies,notably via the following grants:Balancing the impact of City Infrastructure Engineering on Natural Systems using Robots(EP/N010523)City(EP/K021699)and UKCRIC—National Buried Infrastructure Facility(EP/P013635).The visualisations shown in this paper were produced using SketchUp Pro(Inc,2016).
文摘The subsurface space in urban areas is an important asset.However,the information available on this environment is relatively poor compared to above ground information.This paper proposes a Building Information Model(BIM)for underground applications as means to address this information gap.The creation and progressive update of BIM for a constructed artefact ensures that data on the structures is available and can be used throughout its lifetime.A BIM for underground applications integrates data on surface structures,such as buildings,and subsurface infrastructures,such as pipes,along with details of the surrounding ground,the associated soil and rock properties and groundwater regime into a single framework.This approach is demonstrated by applying it to trenchless construction operations,including a microtunnelling project for a new sewer.The data from this extended BIM concept can be interactively used with analysis packages to conduct risk assessments for new construction activities.It also shows how BIM for the Underground can be used throughout the planning,construction and post-construction stages of a project,and,importantly,how this information can be available for future projects.
基金The first author is funded by an Irish Research Council Enterprise Partnership Scheme(IRC-EPS)Postgraduate Scholarship,with Ward and Burke Construction Limited as the industry partner.The third author is supported by the Royal Academy of Engineering(U.K.)under the Research Fellowship Scheme.
文摘In recent years,there has been an increased resort to microtunnelling/pipe-jacking as a means of constructing underground conduits(for water,sewage,gas,and other utilities)to avoid on-street disruption in urban areas.In this paper,technical details of two 1200 mm internal diameter microtunnels in silty sand totalling over 550 m in length are discussed.While average skin friction values are extremely low for both drives suggesting effective lubrication practice,differences in normalised bentonite volumes appear to be responsible for differences in skin friction.Full or near full buoyancy of the pipeline has been demonstrated for the majority of the drive.The frictional stress increase after a stoppage is shown to depend on not only the stoppage duration but also on the normalised lubrication volume.Interpretation of data in the manner presented in the paper is an important means of assimilating experience of microtunnelling in different ground conditions.
