School of Environment, Geography and Geoscience Unit TitleROCK MECHANICS AND ENGINEERING DESIGNAssignment TitlePRELIMINARY ENGINEERING GEOLOGICAL ASSESSMENT AND DESIGN OF ROCK CUT SLOPES & A ROCK TUNNELWord Limit3,000 wordsDue Date12:00hrs noon on Monday 31st May 2021Submission MethodMoodle – Turnitin Coursework Instructions1.0 Introduction The material surrounding surface underground opening in rock forms a complex structure, and as observed by Bieniawski (1984), provision of reliable input data for engineering design of structures in rock is still one of the most difficult tasks facing engineering geologists. Rock mass characterisation is one of the first steps in the rock engineering design process and, as with other areas of geotechnical design, relies heavily on the understanding of the geological setting (the ground profile) and its expected behaviour (ground behaviour), as understood from in situ tests and observations, and supporting laboratory testing. Because of this, the engineering geologist provides a pivotal role in the design process as many key project-planning decisions are made on the understanding and interpretation of the ground conditions. This is especially true in the design of cut slopes and tunnels, where ground conditions and ground behaviour may vary significantly along the tunnel route and slope extent. In many instances, because of the influence of in situ stress and groundwater conditions on rock mass behaviour and stability, the tunnel alignment maybe selected based on the preliminary engineering geological model to ensure favourable ground conditions are encountered. 2.0 Background As an engineering geologist working for a geotechnical consultant you have been asked to report on the engineering and preliminary rock engineering aspects of the proposed realignment of the A4 Bristol Port road away from the Avon Gorge and into a tunnel (Figure 1). To make room for the diversion, cut slopes are required for the approach and the portal. The road realignment runs along the eastern bank of the Avon Gorge from the new Zig-Zag road in the South, through to the Blackrock Quarry in the North. The cut slopes, tunnel and portals will be constructed within the Pembroke Limestone Group, formerly known as the Carboniferous Limestone which all dip at approximately 25 degrees to the south. One of your tasks will be to decide on the size and shape of the tunnel and the vertical alignment, as it will need to avoid clashing with an existing rail tunnel (Figure 1). Relevant figures and data are provided in separate files on Moodle, and include: Virtual filed trip through the proposed road realignmentIntact rock test resultsRock Mass dataDiscontinuity surveysPhotographs of the rock outcrops 3.0 Coursework Assignment The assignment consists of the production of a web-based report, using Google Sites, on the proposed works using the information provided. The web-based report should inform the preliminary design of the cut slopes and rock tunnel, including excavation and support considerations and recommendations. Students should consider inter alia, the following: Ground Profile:Geological assessment (regional geology and geological setting, expected ground conditions, etc)Hydrogeological assessment (identification of potential water sources and potential for water ingress)Ground Characterisation and BehaviourIntact rock assessmentIn situ and induced stress considerationsRock mass strength assessment Kinematic feasibility (eg. ubiquitous joints method)Preliminary support/reinforcement recommendationsRecommendations for further investigation 4.0 Report Structure Part of the assignment is to develop your web development skills and try to use interesting ways to present data. We believe that this will be the way reports will be written and developed in the future. Much more interactive and able to present 3D data much better than conventional written reports. However, you should think about how you will include the following typical technical report section headings. Introduction and Project Brief The Site: Topography; Geological Setting Ground Profile: Stratigraphy; Structural Geology; Hydrogeology Ground Characterisation: Intact rock behaviour; Rock mass behaviour; In situ stress conditions; Induced stress conditions; Discontinuities Ground Behaviour: Stress induced failure (tunnel); Structurally controlled failure (slope and tunnel) Excavation and Support Recommendations Conclusions Recommendations for Further Investigation References 5.0 Submission Deadline and Word Count You should aim to produce a technical and focused wed-based report, and so word count is not an assessed element. However, excluding graphs, tables and figures, circa 3000 words should be adequate. Remember that this coursework accounts for 100% of this 30 credit Module and it is therefore important to your overall marks for this year that you make a concerted effort to produce a well presented, well thought-out and researched web-based report. The Marking Schedule for this coursework assignment is in Annex 1. It is advised that you read and understand this schedule as it will guide you on what is considered important in terms of the assessment. The turnitin submission deadline for this work is at 12:00hrs noon on Monday 31st May 2021. Your submission should be a word document containing the Web Link to your Web Report plus the TEXT that you have used IN YOUR WEB REPORT so that we can check for plagiarism – feedback will be given through Turnitin. GRADE80+70-7960-6950-5940-4930-390-29%Web structure, English and presentationExcellent with few or no errors in organisation, structure, grammar, spelling, format, and presentation. Innovative use of web functionality to present data in an informative and original format.Very good presentation, organisation, grammar, spelling, punctuation. Very good use of web functionality to present data in an informative and original format.Good organisation, structure, use & flow of language, grammar, spelling, and format. Good quality plots and geological sections. Good use of web functionality to present data in an informative and original format.A satisfactory attempt to follow directions regarding organisation, structure, use and flow of language, grammar, spelling and format. Satisfactory use of web-fuctionallity.A basic attempt to follow directions regarding organisation, structure, use and flow of language, grammar, spelling and format. Basic quality plots, geological sections, and no attempt to use web in an innovative way to present data.Serious problems with a number of aspects of language and presentation. Work is either severely under/over-length. FAILNo attempt to follow directions in terms of organisation, structure, use and flow of language, grammar, spelling and format. Acutely deficient in all aspects. FAIL20Ground CharacterisationExcellent work which shows a clear understanding of the subject matter with original thought and analysis. Clear and well articulated.Very good work, which is clearly written, well argued and covers the subject matter in a thorough, thoughtful and competent manner. Contains some originality of approach, insight or synthesis.A very good, well presented piece of work covering much of the subject matter and which is clearly and lucidly written. Good attempt to consider and evaluate the material presented.Work that demonstrates understanding of the topic area with some attempt to discuss material.Adequate work that attempts to address the topic and demonstrates some understanding of the basic aspects of the subject matter.Work attempts to address the problem but is substantially incomplete and deficient. FAILNo serious attempt to address the problem and manifests a serious misunderstanding of the requirements of the assignment. FAIL30Design ConsiderationsProfessional quality designs for both cut slope and tunnel with good use of software backed up by hand calculations. Design goes beyond preliminary design requirements.Very good quality designs for both cut slope and tunnel with good use of software backed up by some hand calculations. Design goes a little beyond preliminary design requirements.Good quality designs for both cut slope and tunnel with good use of software backed up by some hand calculations. Design meets preliminary design requirements.Workable designs for both cut slope and tunnel with good use of software not backed up hand calculations. Some aspects missing but design meets preliminary design requirements.Basic designs for both cut slope and tunnel with some use of software but not backed up hand calculations. Some aspects missing but design meets preliminary design requirements.Some simple analysis and design attempted but not integrated with the geology or data. Design elements missing. FAILNo attempt to carry out any coherent design of either the tunnel or cut slope. FAIL30Literature Review and Reference ListWide research incorporating up to date relevant original material. Accurate citation and use of referencesGood evidence of research and good use of source material. Good use and presentation of references.Evidence of research in the topic area and satisfactory use of sources and references.Evidence of research in the topic areas extending beyond key texts.Topic is researched using mainly books and Internet. Attempts to use and present references according to conventionTopic not researched and weak attempt to use references which are all Internet based. FAILTopic not researched or referenced. FAIL.20 Avon Gorge A4 Road Realignment – Marking Criteria
