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\nThis TWf/ASUC Guidance is available as a free download from [www.twforum.org.uk](www.twforum.org.uk and)[ and](www.twforum.org.uk and)[ ](www.twforum.org.uk and)[www.asuc.org.uk](www.asuc.org.uk)  \nDocument: TWf2023:02  \nNOTE: If you need to print this document, be aware that the pages are prepared with alternate (even) pages offset for your duplex (double sided) printing.  \nASUC ISA REGISTERED TRADE ASSOCIATION  \nMembers of the Working Group  \nThe Temporary Works Forum (TWf) gratefully acknowledges the contribution made by the working group and contributors in the preparation of this guidance:  \nContributors included:  \nSimon Smith  \nDavid Thomas Konstantinos Angelopoulos Mick Durie  \nMichael Johnson Rob Millard Matthew Newis Lewis O’Connor Martyn Ostcliffe Malachy Ryan Tony Suckling Rob Withers  \nContractors Design (CDS) Ltd (Convenor) UK TWf (Secretary)  \nKier Ltd Deconstruct (UK) Ltd Piledesigns Ltd  \nDE Construction Solutions Ltd Abbey Pynford Ltd Basement Force Ltd  \nHealth and Safety Executive (HSE) Alan White Design Ltd A2 Studio (A squared studio)  \nAssociation of Specialist Underpinning Contractors (ASUC)  \nThanks are due also to: Mark Beeston (Balfour Beatty), Ray Filip (RKF Consult), Archie McVicar (Balfour Beatty) and Alek Widernik (Contractors Design (CDS) Ltd) .  \nSynopsis  \nUnderpinning as a concept is generally understood by most people, but its mechanics and feasibility is  \nless so. This document provides the reader with the key information necessary when underpinning is being considered on a project. Ultimately, the success of any project lies in proper planning, allowing sufficient time to gather the right level of information and appointing experienced specialists. This is especially true for underpinning where the consequences of getting it wrong can be catastrophic.  \nDisclaimer  \nAlthough the Temporary Works Forum and ASUC does its best to ensure that any advice, recommendations or information it may give, either in this publication or elsewhere is accurate, no liability or responsibility of any kind (including liability for negligence) howsoever and from whatsoever cause arising, is accepted in this respect by the TWf/ASUC, its servants or agents.  \nReaders should note that the documents referenced in the Bibliography are subject to revision from time to time and should therefore ensure that they are in possession of the latest version.  \nContents  \nTo navigate to page-hover over an item below and ‘click’. Return to contents by clicking on the ‘Return to the contents’ at the bottom of every page.  \nSection Page Members of the Working Group  ................ 2  \nSynopsis  ................................... 2  \nDisclaimer  .................................. 2  \nContents  ................................... 3  \n1 .0 Introduction  ............................ 4  \n2 .0 Scope  ................................. 4  \n3 .0 Health and safety matters  ................ 5  \n4 .0 Key risks  .............................. 5  \n5 .0 Planning  ............................... 6  \n6 .0 Design requirements in underpinning  ....... 8  \nSummary of good practice guidance: .......... 8  \nShoring: ............................... 10  \nLoads: ................................ 10  \nVertical – Failure mechanism: Settlement ...... 10  \nHorizontal – Failure mechanism: Sliding/overturning ....................... 11  \nSection Page  \nAdjacent structures ...................... 12  \nDesign safety considerations ............... 13  \nUnderpinning as part of retaining wall construction – Basement construction ........ 14  \nDeep underpinning, retaining walls and multi-level underpins .................. 15  \nVertical loads ........................... 15  \nLoad transfer ........................... 16  \nPre-loading of ground, structures or propping systems...................... 16  \nPermanent works in the temporary condition ... 18  \nMinimum underpinning depths .............. 18  \n7 ","cbCaicJBtEkpxc2q","https://ap.wps.com/l/cbCaicJBtEkpxc2q","pdf",951693,22,"English","# Synopsis\n# Disclaimer\n# 1.0 Introduction\n# 2.0 Scope\n# 3.0 Health and safety matters\n# 4.0 Key risks\n# 5.0 Planning\n# 6.0 Design requirements in underpinning\n## Summary of good practice guidance\n## Shoring\n## Loads\n## Vertical and horizontal failure mechanisms\n## Adjacent structures\n## Design safety considerations\n## Underpinning as part of retaining wall construction\n## Conclusion\n# References\n# Bibliography","[{\"question\":\"What is underpinning and how does the document define it?\",\"answer\":\"The document defines underpinning as the downward extension of existing foundations using a method of staged excavations and replacement of soil with concrete (reinforced or unreinforced).\"},{\"question\":\"Who is the guidance aimed at?\",\"answer\":\"The target audience includes those involved at project conception, such as planning consultants, architects, consulting engineers, developers, principal designers, and lay clients, and it also benefits contractors and temporary works specialists.\"},{\"question\":\"Why is proper planning emphasized when underpinning is considered?\",\"answer\":\"Success depends on proper planning, including allowing sufficient time to gather the right information and appointing experienced specialists, because the consequences of getting underpinning wrong can be catastrophic.\"}]","TWf2023 - 02 - Underpinning: Good practice guidance - June 2023 | PDF",1792823526,55]