SR99 Bored Tunnel-Assessment of Settlement Impacts ... - SCATnow

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trough, the physical properties and condition of the structure itself, and theorientation of building elements (e.g. walls and frames) with respect to the tunnelaxis.An important distinction can be drawn between the expected damage levels forbuilding elements oriented parallel to and perpendicular to the tunnel axis. Generallyspeaking, the S-shaped settlement curve that forms along a section parallel to thetunnel axis – the “Longitudinal Settlement Curve” – places lower demands on, andthus causes less damage to, building elements oriented parallel to the tunnel axis,when compared to the settlement curve that forms along a section perpendicular tothe tunnel axis – the “Transverse Settlement Curve” – and the damage the damagethe settlement in the shape of this curve causes to building elements orientedperpendicular to the tunnel axis. In other words, if two identical unreinforcedmasonry (URM) walls are oriented parallel to and perpendicular to the tunnel axis atthe same location, the settlement trough will cause more damage to theperpendicular wall than to the parallel wall.The difference in damage levels between the parallel and perpendicular directions isexplained by the fact the transverse settlement curve induces higher slopes,curvatures, lateral strains, and lateral displacements than the longitudinal settlementcurve. Transverse settlement curve develops permanent deformations in a building,while the longitudinal settlement curve develops transient deformations, which occuronly as the TBM passes a particular location. After the TBM passes, the buildingdeformations induced by the longitudinal settlement curve reverse, so that buildingelements oriented parallel to the tunnel axis tend to return approximately to theiroriginal configurations, although of uniform settlement, and stress levels.Thus, when estimating building damage levels, it is generally conservative to onlyconsider building deformations induced by transverse settlement curves: thedeformations induced by longitudinal settlement curves are of a lower magnitudethan the deformations induced by transverse curves; and the longitudinal settlementcurves are transient, whereas the transverse settlement curves are permanent. Forthese reasons, in the present study, estimates of building damage due to tunnelingwere based only on the transverse settlement curves predicted at each buildinglocation. This assumption was validated by performing sample estimates of damageinduced by longitudinal settlement curves, and it was found that these damage levelswere always lower than the damage levels induced by the transverse settlementcurves at the same location.The Alaskan Way Viaduct & Seawall Replacement Program March 2010Proposed SR 99 Bored Tunnel - Assessment of Settlement Impacts to Buildings 24Public Disclosure Request 11-0123 for Elizabeth Campbell - 2nd installment
6.0 Results of Structural Analyses6.1 GeneralResults of the structural analyses for buildings along the tunnel alignment indicatethe potential for damage is highly variable along the alignment. Utilizing the B&Canalysis, the damage prediction for the buildings along the alignment ranges from“Negligible” to “Very Severe”, even assuming good tunneling practice that involvesground losses less than 0.5%. This analytical evaluation of the buildings was in manycases influenced by the qualitative evaluation. Table 3 below summarizes theanticipated level of damage to the buildings, including the qualitative assessment,from both the tunnel and portal wall construction.Table 3. Breakdown of Anticipated Building DamageDamageCategory# of Buildings Impacted fromTunnel ConstructionColor Highlighting Building onDrawings in Appendix ANegligible 111 NoneVery Slight 22 NoneSlight 19 YellowModerate toSevere4 RedSevere to VerySevere2 RedTotal 158In Section 3, a number of factors were introduced which could impact the results ofthe qualitative evaluation. Some of these factors are discussed in more detail in thesections below.6.2 Building FunctionIn addition to tunnel-induced settlements potentially damaging building structuresand/or nonstructural elements, there is a potential risk to operations within existingbuildings, in particular those with highly sensitive equipment or those occupanciesconsidered by the building code as essential facilities. In these cases, the building’sfunction or equipment can be less tolerant to the effects of settlement than thebuilding itself.Buildings with essential functions along the tunnel alignment include a fire stationand communications facilities, where the damage threshold for acceptable buildingperformance may be lower. Buildings with sensitive equipment include printingpresses, where large equipment must remain level and balanced.The Alaskan Way Viaduct & Seawall Replacement Program March 2010Proposed SR 99 Bored Tunnel - Assessment of Settlement Impacts to Buildings 25Public Disclosure Request 11-0123 for Elizabeth Campbell - 2nd installment
Page 5 and 6: Table of Contents1.0 EXECUTIVE SUMM
Page 7 and 8: Proposed SR 99 Bored Tunnel -Assess
Page 9 and 10: The damage classification for the r
Page 11 and 12: 2.0 Program Description & Backgroun
Page 13 and 14: 2.2 Tunnel Project DescriptionThe T
Page 15 and 16: 2.2.3 North Access Project Descript
Page 17 and 18: 3.0 Building AssessmentThe tunnel a
Page 19 and 20: . History of settlement - based upo
Page 21 and 22: 4.0 Settlement and Ground Movement4
Page 23 and 24: Figure 3. Generalized Transverse Se
Page 25 and 26: 5.0 Building Response to Excavation
Page 27 and 28: Table 2. Building Damage Classifica
Page 29: tunnel axis), the settlement trough
Page 33 and 34: Therefore, high-rise buildings alon
Page 35 and 36: Table 4. Summary of Building Damage
Page 37 and 38: PROPERTY IDPROPERTY ADDRESSAPPROXIM
Page 47 and 48: 7.0 ReferencesAttewell, P.B.; Yeate
Page 49 and 50: Appendix ATunnel Alignment Plan She
Page 51 and 52: A1Legend! ! SeawallPiersAreawaysTun
Page 53 and 54: T161NOTES :1) ASSESSMENT OF DAMAGE
Page 55 and 56: A3LegendMONORAILEBIAreawaysTunnelTu
Page 57 and 58: Appendix BBuilding Damage Classific
Page 59 and 60: Figure B-1. Graphical Illustration
Page 61 and 62: Appendix CBuilding Assessment Forms
Page 63 and 64: List of Abbreviations Used in Build
Page 65 and 66: Distance to Tunnel:• Horizontal o
Page 67 and 68: example, T311 and T312 are the same
Page 69 and 70: Appendix DBoscardin and Cording Ana
Page 71 and 72: Table of Contents1.0 B&C ANALYSIS M
Page 73 and 74: 1.0 B&C Analysis MethodThe building
Page 75 and 76: Offset, Yδε hLβDeparture from tu
Page 77 and 78: Figure D-1. Building Location Coord
Page 79 and 80: 1.00.90.80.7G((X-XT)/KZ)0.60.50.40.
Page 81 and 82:
2.0 B&C Damage ClassificationsTable
Page 83 and 84:
3.0 E/G RatioE/G is based upon Tabl
Page 85 and 86:
4.0 Building HeightBuilding height
Page 87 and 88:
5.0 Foundation DepthThe analysis to
Page 89 and 90:
Appendix EMonitoringThe Alaskan Way
Page 91 and 92:
Table of Contents1.0 INTRODUCTION .
Page 93 and 94:
1.0 IntroductionThe potential groun
Page 95 and 96:
2.0 Basic MonitoringManual survey p
Page 97 and 98:
3.0 Tilt Meter Monitoring3.1 Goals3
Page 99 and 100:
4.0 GPS Monitoring4.1 Goals4.2 Impl
Page 101 and 102:
5.0 Automated Monitoring Total Stat
Page 103 and 104:
6.0 Distributed Data Acquisition6.1
Page 105 and 106:
The emerging capability of wireless
Page 107 and 108:
7.0 Levels of MonitoringEach buildi
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SR99 Bored Tunnel-Assessment of Settlement Impacts ... - SCATnow

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