Geotechnical Desk Study - Islington Council

More documents

Recommendations

Info

Geotechnical Desk Study 10. Recommendations for Further Work 10.1 Contamination It is recommended that a Phase 1 assessment is made of the likely contamination that may have been caused by the glass bottle works and latterly by the packing case factory. 10.2 Ground Investigation It is recommended that a ground investigation is carried out within the tarmac/concrete area. This is primarily required to identify the cause of the longitudinal cracking and provide sufficient data for foundation design of any new structures. The ground investigation is likely to comprise the excavation of three trial pits within the cracked area of tarmac and adjacent area at the top of the railway cutting to investigate the cause of the movement. In addition three boreholes should be carried out across the site area where new buildings may be constructed. The depth of the boreholes would be dependent on the layout and loading any proposed structures and the type of foundations envisaged. It is recommended that the length of the boreholes should be at least 20m to allow the design of piled foundations if required. If the Phase 1 assessment identifies the possibility of the presence of significant contamination, the scope of the ground investigation should be extended to cover the required sampling and chemical testing. It is also recommended that a series of hand dug trial pits are excavated adjacent to the east side retaining wall to identify the founding depth of this existing wall. A series of horizontal trial cores should also be carried out through the (exposed) face of the retaining wall, to determine the wall geometry and the fill material beyond. The proposed ground investigation is likely to cost in the order of £15,000 to £20,000. 10.3 Retaining Structures The discussion in section 7.3 has indicated the poor condition of the existing retaining walls and the Community Centre end wall, particularly in respect to horizontal and vertical fracturing, along with lateral movement. Whilst the majority of the retaining wall structures will require replacement, there are some sections of the East side Boundary Wall and Community Centre end wall, where local remedial works could be implemented. Stitch-and-Grout repair of the major fractures in the wall could be employed (using stainless steel bars criss-crossing the fractures in a random matrix) in an attempt to recreate monolithic action and a more robust structure. The remedial works offer a low-cost structural improvement, coupled with the installation of 3D measuring devices on the exposed wall faces either side of the fracture lines, with survey data collected at monthly intervals and a review of this data made after 12 months could be employed. On the other hand, there are a number of limitations or caveats which have to be noted, particularly as no historical monitoring of the East Side Boundary Retaining Wall is available to establish the trend in fracture propagation/enlargement or in geometric alignment (horizontally and vertically): • The essentially weak form of structure will be only partially relieved by re-establishing a degree of monolithic action in the wall. Re-emergence of fracturing is likely in due course • Structural integrity of the wall only partially addressed; in particular, the problem of rotational movement of the wall about its base and lateral displacement (if this is still occurring) Complete replacement of the retaining wall structures with a new piled wall, designed to accommodate the actual site conditions, is a long-term solution. 5044006/002 Geotechnical Desk Study (2).doc 20
Geotechnical Desk Study The new wall, in the case of the East side Boundary Wall, could be erected in front of the existing, reducing any disruption to the owners of residential properties immediately behind the wall. Clearly, this is an expensive solution with a number of disadvantages, including: • Risk to existing structure stability during construction of new piled wall • Reduction in land area immediately in front of the existing wall In accordance with our comments presented in Section 7.4, we consider that in advance of applying local repairs to the East Side Boundary retaining wall, ground stabilisation would be required. In case of structure replacement with new retaining walls, we propose deep foundations using steel or concrete piles, which would be less sensitive to the surface ground movement. 5044006/002 Geotechnical Desk Study (2).doc 21
Page 1: Highbury Roundhouse Youth & Communi
Page 4 and 5: Geotechnical Desk Study Contents Se
Page 6 and 7: Geotechnical Desk Study Glossary of
Page 8 and 9: Geotechnical Desk Study 2. Sources
Page 10 and 11: Geotechnical Desk Study Statutory U
Page 12 and 13: Geotechnical Desk Study 1991 to 199
Page 14 and 15: Geotechnical Desk Study 6. Ground C
Page 16 and 17: Geotechnical Desk Study level), is
Page 18 and 19: Geotechnical Desk Study 8. Geotechn
Page 22 and 23: Geotechnical Desk Study 11. Summary
Page 24 and 25: Geotechnical Desk Study 12. Referen
Page 26: Geotechnical Desk Study A.1 Site Pl
Page 36 and 37: Geotechnical Desk Study B.1 BGS Bor
Page 38 and 39: 1 © All rights are reserved by the
Page 40 and 41: Geotechnical Desk Study Appendix C
Page 42 and 43: Geotechnical Desk Study Photo 1 : E
Page 44 and 45: Geotechnical Desk Study Photo 5 : H
Page 46 and 47: Geotechnical Desk Study Photo 9 : (
Page 48 and 49: Geotechnical Desk Study Photo 11 :
Page 68 and 69: Geotechnical Desk Study Appendix D
Page 71 and 72:
Geotechnical Desk Study Appendix E
Page 75 and 76:
Geotechnical Desk Study Appendix F
Page 82 and 83:
Geotechnical Desk Study Appendix G
Page 84 and 85:
Title: A3 LANDSCAPE Legend: Disclai
Page 99 and 100:
Page 1 of 2 Manish, Kumar From: Enq
Page 101 and 102:
Page 1 of 2 Manish, Kumar From: Pla
Page 103 and 104:
INSTALCOM LTD CIVILS AND CABLING IN
Page 105 and 106:
6. When excavating around, moving o
Page 107 and 108:
GC as-built 2008v1.1 0 yds 100 200
Page 109 and 110:
Page 2 of 2 ATKINS The Hub, 500 Par
Page 111 and 112:
Asset Location Search Search addres
Page 113 and 114:
Asset Location Search For your guid
Page 115 and 116:
Asset Location Search Clean Water q
Page 117 and 118:
Extended GIS print Page 1 Printbox
Page 119 and 120:
Based on the Ordnance Survey map wi
Page 121 and 122:
Terms and Conditions All sales are
Page 123 and 124:
SCALE: Not to scale USER ID: robe28
Page 125 and 126:
Page 2 of 2 Road, Epsom, Surrey KT1
Page 128:
...\WC-Tq\WC-TQ3185SW.dwg 20/05/200
Page 131 and 132:
Page 2 of 2 Hazeldean, Station Road
Page 133 and 134:
Page 1 of 2 Manish, Kumar From: Tra
Page 136 and 137:
Page 1 of 2 Manish, Kumar From: Kat
Page 138 and 139:
Page 1 of 2 Manish, Kumar From: Str
Page 140 and 141:
Page 1 of 2 Manish, Kumar From: Pau
Page 142 and 143:
Page 1 of 2 Manish, Kumar From: Pla
Page 144:
Linesearch - Welcome http://www.lin
Page 149 and 150:
Page 2 of 2 This message has been s
Page 151 and 152:
Page 2 of 2 SCHEME REF NO: 10244/MK
Page 153 and 154:
Your ref: 10244/MK Our ref: AD/NRSW
Page 155 and 156:
Page 2 of 2 binding. The ultimate p
show all

Geotechnical Desk Study - Islington Council

Create successful ePaper yourself

Delete template?

Save as template?