1 / 49

Xdisp Webinar

Xdisp Webinar. Oasys. Today’s Presenter. Zeena Farook Geotechnical Application Engineer. GoToWebinar Attendee Interface. 1. Viewer Window. 2. Control Panel. If you cannot hear, please check this setting. Who is Oasys?. Software house of Arup

ella
Download Presentation

Xdisp Webinar

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. XdispWebinar Oasys

  2. Today’s Presenter Zeena Farook Geotechnical Application Engineer

  3. GoToWebinar Attendee Interface 1. Viewer Window 2. Control Panel If you cannot hear, please check this setting

  4. Who is Oasys? • Software house of Arup • Formed in 1976 to develop software for in-house and external use • Most developers are engineers who have moved to programming • In recent years have added marketing, sales, and development staff worldwide • Network of Agents

  5. Structural Geotechnical Document Management Crowd simulation CAD Sustainability

  6. Oasys Customers

  7. Objectives • Appreciate Xdisp theory and its use in industry • Set up a simple tunnel and excavation analysis • Set up a simple Building Damage and Utility Damage Assessment • Demonstrate the Graphical Input feature

  8. Xdisp – An introduction Soil Displacements due to Excavations

  9. Xdisp • Calculates ground movement due to excavations • Typical use: • Tunnel excavations in soft ground (i.e. nothard rock tunnelling) • Shafts • Retained cuts (e.g. deep basements) • Mined excavations A A

  10. Xdisp analysis methods • Tunnel induced ground movements • Mining induced ground movements • Excavation induced ground movements

  11. 1. Tunnel induced ground movements 1.1 Generalised form of movement • Equations for the curves are generated from the normal or Gaussian distribution • Normal distribution relationship shows a close match to tunnelling induced case study movements at ground and sub-surface levels. • Can be difficult to achieve similar results using FE (Addenbrooke & Potts St James’s Park FE analysis described in CIRIA 2001)

  12. 1. Tunnel induced ground movements 1.1 Generalised form of movement • Relationship is ‘empirically’ based, not analytically based (i.e. one that uses soil properties such as strength, stiffness etc.) • Parameters of importance are: • Volume Loss (m³/ m run) • Trough width parameter (k) • => The complete three dimensional behaviour of the ground due to tunnelling can be defined

  13. 1. Tunnel induced ground movements 1.2 Volume Loss Definition: Ratio of the additional volume of excavated ground over the theoretical volume of the tunnel Volume loss depends on many factors, including: • Tunnelling method (TBM type or SCL) • Ground and groundwater conditions • Flexibility of liningetc. Many authors have provided guidance on volume loss based upon case studies. Empirical approach considering C/D and P/D proposed by Macklin (1999)

  14. 1. Tunnel induced ground movements 1.2 Trough Width Parameter • Trough Width Parameter Clay (typically k = 0.5) Sand (typically k = 0.3)

  15. 1. Tunnel induced ground movements 1.2 Trough Width Parameter • Other authors have proposed relationships of i to k for different conditions at surface: • • O’Reilly & New (1982), surface displacements • • Boscardin, surface displacements • • New & O’Reilly (1991), surface displacements, multi layered deposits • Can use the above relationships, however, many practitioners use i = k / zo • for surface displacements. This is generally adequate and simpler (this is • ‘user defined k’ in XDISP) • Either of the following is commonly used for sub-surface displacements: • • Mair et al (1993) – only really for tunnelling in clay (because k = 0.5 at • surface) • • New & Bowers (1994)

  16. 2. Mining induced ground movements • Method proposed by Ren et al (1987) • Defines surface displacements

  17. 3. Excavation induced ground movements 3.1 Surface Displacement Curves • Surface displacement curves from CIRIA C580 • Can input curves from empirical data

  18. 3. Excavation induced ground movements 3.2 Sub surface Displacement Curves • Initially derived from surface curve where displacement=0 at base • but sub surface curves more realistic • Derived from empirical data or FE analysis of excavation in similar soil • Detailed method included intraining materials

  19. 3. Excavation induced ground movements 3.3 Corner Stiffening • Previous (no corner stiffening) • New (corner stiffening*) * Fuentes R. and Devriendt M. (2010). Ground movements around corners of excavations - An empirical calculation method. Journal of Geotechnical and Geoenvironmental Engineering. Volume 136, Issue 10, pp. 1414-1424.

  20. Xdisp input • Tunnel/mine type • Displacement points for calculation (line, grid, point) • Displacement points for plotting (line, grid, point) • Tunnel • Wall installation & excavation • Mine • Buildings

  21. Xdisp Inputs - Preferences and defaults • Tabbing past a table cell with a default will fill the cell with the default value • Defaults can also be edited – click in the grey cell at the top

  22. Xdisp Inputs - Table tips • = in a cell copies the cell above • == in a cell copies the rest of the line above • In long tables, ctrl-G lets you type in the line to go to • Right-click brings up a whole list of options – modify probably the most useful

  23. Xdisp output • Ground movement • Displacements • Building Damage Assessment • Utility Damage Assessment

  24. Case Study Copenhagen Metro

  25. Copenhagen Metro – The design brief • 15.5km metro line with 17 underground stations • Stations are cut-&-cover structures, retained within a station box of either secant piles or diaphragm walls. • Geotechnical challenges include the requirement to limit settlements

  26. Copenhagen Metro – The settlement assessment • Oasys XDisp was used to calculate the settlements at the ground surface caused by the construction of the tunnels.

  27. Copenhagen Metro – The settlement assessment • Screening - identification of any structure where the predicted settlement from bored tunnels is more than 5 mm or the predicted slope is more than 1/500. • XDisp showed how specific structures performed in relation to the damage categories using building damage interaction charts • This list was used to identify buildings where building protection may be required, allowing a means of assessing the contractor’s proposed works during tender evaluation.

  28. XdispRunthroughTunnel and Excavation Analysis Set up a tunnel and excavation problem Input displacement lines and grids Input tunnels and excavations Input sub surface displacement curves Run analysis Navigate tabular and graphical outputs Export tabular results Plot graphs Manipulate 3D Graphics

  29. Xdisp – Further analysis • Building Damage Assessments • Utility Damage Assessments • Other recent developments

  30. 1. Building Damage Assessments 1.1 How is damage defined? Categories of damage (order of increasing importance): • Visual appearance or aesthetics • Serviceability or function • Stability Commonly used system which expands on above is that proposed by Burland et al (1977) Increasing foundation movement

  31. 1. Building Damage Assessments 1.1 How is damage defined

  32. 1. Building Damage Assessments 1.2 Assessment method Three stages defined: Stage 1 – Preliminary assessment Settlement contours Stage 2 – Second stage assessment Building Damage Assessments Stage 3 – Detailed evaluation Important to note that criteria specified in the above assessment methods rely on the structure being in a ‘reasonable’ state of repair. Volume 1, Chapter 3 of the book “Building response to tunnelling, case studies from construction of the Jubilee Line Extension project, London

  33. 1. Building Damage Assessments 1.3 Assessment method – Stage 2 Idealisation of façade or wall of building to behave like a deep elastic beam, see Burland (1995) Has been shown to be reasonable for brick masonry structures. Examples of use for reinforced concrete structures in (CIRIA JLE, 2001, Vol.2)

  34. Tension Compression Tension Hogging Sagging Hogging VERTICAL SETTLEMENT (W), HORIZONTAL DISPLACEMENT (V) AND GROUND STRAIN PROFILE (after Lake, Rankin and Hawley, 1992)

  35. 1. Building Damage Assessments 1.4 Specific Building Damage Assessments Export Results with images for each chart and excel files of structures displacement and strain

  36. 1. Building Damage Assessments 1.5 Generic Building Damage Assessments Transects Polyline Calculates displacements, strains and damage categories for each transect along a polyline

  37. XdispRunthroughSpecific Building Damage Assessment

  38. 2. Utility Damage Assessments 2.1 How is utility damage calculated Input Output Utility displacements and Utility dimensions strain, pullout, joint rotation Acceptance criteria can be set to determine if the utility fails This is summarised in the tabular output and plotted in the graphs

  39. 2. Utility Damage Assessments 2.2 Generic Utility Damage Assessment Utilities lie along transects and strain, pullout and joint rotation calculated for each Transects represent utility Polyline

  40. XdispRunthroughSpecific Utlity Damage Assessment

  41. 3. Other recent developments 3.1 CAD Imports DXF Background Import DXF Element Import

  42. 3. Other recent developments 3.2 Graphical inputs Data Input via 3D Graphics view

  43. XdispRunthroughGraphical Input Feature

  44. Pdisp Developments • Xdisp • Calculates ground movement due to excavations • Pdisp • Calculates displacements due to the application of a pressure, either loading or unloading PDisp XDisp

  45. When use Xdisp/Pdisp? • Xdisp • Calculates ground movement due to excavations • Pdisp • Calculates displacements due to the application of a pressure, either loading or unloading

  46. Objectives • Appreciate Xdisp theory and its use in industry • Set up a simple tunnel and excavation analysis • Set up a simple Building Damage and Utility Damage Assessment • Demonstrate the Graphical Input feature

  47. What next? • Support: • Try new Tutorial Manual:http://www.oasys-software.com/xdisp-tutorials.html • Online training movies • Web site and technical FAQs • mailto:oasys@arup.com • Telephone support at +44 (0) 191 238 7559

  48. Any Questions?

More Related