Building and structure design
We regularly design projects of reinforced concrete and steel framed construction, steel concrete and other composite construction, masonry, timber, structural aluminium and glass construction.
Designs of more complex structures are undertaken, including antennae, masts, space frames, tensile, cable stayed, stressed skin, post-tensioned and or pre-stressed structures.
Dynamic analysis and design of more dynamically sensitive or critical structures can be undertaken.
Foundation design
Foundation designs of the full spectrum of buildings and structures is undertaken including low rise to multi storey structures.
We regularly commission and control foundation and ground investigation.
In addition to more straightforward conventional strip or pad foundation design more specialist foundation designs and analysis are undertaken.
These include foundation immediate and long-term settlement analysis, bored and driven piled foundations, reinforced concrete ground beam, raft, deep and water retaining basement construction.
Design of foundations upon shrinkable clays soils, e.g. London Clay Formation or Oxford Clay is regularly undertaken. Design solutions adopting deep pad or piled foundations with reinforced concrete ground beams or slabs are regularly used where particular adverse ground conditions and or close proximity of trees require.
Foundations upon chalk can present foundation difficulty, in particular where chalk solution features are prevalent. We have expertise in the design of alternative foundation solutions where required to overcome difficult chalk ground conditions.
Designs of underpinning or other foundation stabilisation or improvement works are part of the expert comprehensive design service we provide.
Ground and foundation investigation
Investigation to have a proper understanding of the ground and foundation conditions, including those of adjacent buildings and structures, is crucial to enable proper and efficient design of foundations, structures, ground works, retaining walls and earth supporting systems.
Investigation should include detailed visual inspection of the site and adjacent buildings to ascertain the visible prevailing conditions.
Ground investigation may include straightforward trial pit exploratory work of ground and foundations. Deeper investigation may be achieved with hand-augured boreholes or with advanced techniques including machine mini – boreholes, shell and auger boreholes and dynamic probing.
Radar investigation may be used in appropriate circumstances to assess variation in ground strata.
Monitoring of structures, foundations and adjacent or supporting ground may form part of a proper investigation.
Site investigation is normally supported with appropriate laboratory testing of soil samples.
Investigation where appropriate may include load testing of foundation or anchorage systems. These are commonly related to pile tests and ground anchors tests for load capacity and movement data.
Following completion of appropriate site and laboratory investigation and any necessary ground or soil-structure analysis, detailed, clear and concise reports are prepared as appropriate and to the extent required by the brief.
Refurbishment and conservation design
We provide professional services and have considerable experience in the refurbishment and or conservation of existing and historic buildings.
Where appropriate this will include advice and design in respect of change of use.
All such refurbishment and remedial schemes should be carried out in close liaison with the statutory authorities, obtaining all required planning, listed and historic building consents, for which we can make application on behalf of our clients.
Where appropriate archaeological investigations and ancient monument statutory approvals may be necessary.
Masts and Towers
Design of these more specialist or complex structures are undertaken, with relevant guidance including Eurocode 3: Design of steel structures – Part 3-1 Towers, masts and chimneys – Towers and masts and Eurocode 1: Actions on structures – Part 1-4: General actions – Wind actions.
Surveys, appraisals, structural investigation, advice and reports
We are regularly engaged to undertake surveys and investigation of existing buildings or structures and to advise and or report upon various specific aspects including building and structural condition, adequacy for proposed use or implications of any proposed building or structural alteration or extension.
Following and in conjunction with initial research and investigation and appraisal we would normally meet with the client, discuss and provide advice first hand, subsequently and dependent on our findings and instructions, provide report as appropriate.
Generally, such investigations, advice and or reports may be divided into four categories those for residential properties (houses or flats), buildings for commercial office or shop or retail use, industrial buildings and structures (free-standing or attached to buildings).
Residential properties – houses and flats
Whilst surveys, appraisals, investigation, advice and reports can be tailored to meet precise requirements, they typically are required for three purposes:
• For sale or purchase of residential property
• For advice upon apparent foundation subsidence, building and or structural defect
• For advice upon implications of proposed building or structural alteration or extension or change of use
For sale or purchase of residential property, three types of advice or report are generally offered:
1.Structural Survey Advice or Report
Whilst a report can be tailored to meet your specific requirements it will normally cover as appropriate aspects including:
• Reference to the brief and reasons for the report.
• General description
• Condition of roofs, party wall and chimney stacks
• Foundation movement and associated damage
• Structural general condition
• Energy efficiency, cold bridging and condensation
• External window and door joinery
• Internal door joinery
• External rainwater goods and plumbing
• Fire safety and means of escape in case of an emergency
• Damp survey
• Condition of below ground drainage
• Condition of the building services
• Sound transmission
• Building regulations and town planning
• Party wall matters
• Summary
2.Initial survey appraisal advice
This may be typically limited to the main structural elements and or foundation movement and associated damage affecting the property, with only brief comment upon other associated building aspects.
Following and in conjunction with initial research and investigation and appraisal we would normally meet with the client, discuss and provide advice first hand, subsequently and dependent on our findings and instructions, provide a brief letter (typically one page – two pages), or a brief extended letter or report setting out the main points discussed (typically three – ten pages). This may include, reference to the letter of instructions brief, and or a brief and reasons for the extended letter or report.
3.Homebuyers report
A Homebuyers report as defined by the Royal Institution of Chartered Surveyors guidance can be provided.
Building and or structural defect or subsidence investigation reports
For advice upon apparent foundation subsidence, building and or structural defect, two types of advice and or report are generally offered (please refer also to subsidence investigation, remedial design and control):
Structural advice and or Report
Report will normally cover aspects as appropriate including:
• Synopsis
• General description
• The extent of the defect and or movement and associated damage
• The related structure and implications generally
• Initial advice and opinion upon cause of the defect and or movement and associated damage
• Health and safety
• Remedial measures
• Further research and investigation including monitoring of any movement
• Summary
Initial survey advice and or report
Appraisal and report for adequacy for proposed use or implications of any proposed building or structural alteration or extension
When an appraisal and advice upon the implications of a proposed building or structural alteration or extension or change of use is required, this will involve initial research of related information and documents and the careful visual inspection of the building or structure and appraisal of the proposed structural alteration or change of use.
Our advice and report can detail as required the implications of any proposed building or structural alteration, extension or change of use.
Subsidence investigation, remedial design and control
Subsidence – ground and foundation movement with associated damage
In London and the south east of England subsidence has been generally associated with problems caused by clay soil movement and the effects of trees, because of the prevalence of outcropping clay.
However, it should be appreciated this is by no means the only or principal cause, nor the only possible cause in these areas.
Problems of major foundation movement and damage can be due to other causes.
For example, these may include subsidence in mining areas, collapse and movement of solution features in chalk, adverse groundwater affects upon loose on granular / sandy soils, loessic brickearth instability, settlement or failure of made ground, landslip or retaining wall failure.
Initial appraisal – advise and diagnose – initial research and visual inspection
Where requested to advise and diagnose problems of suspected subsidence, in the first instance we would usually carry out initial research and an initial visual inspection to assess the extent and seriousness of the movement and damage, general conditions prevailing, probable causes, further research and investigation and immediate remedial or temporary works required.
Extent of movement and damage
The key issues to determine are whether the movement and associated damage is unacceptable and or is likely to continue or deteriorate without remedial measures.
Having assessed the seriousness of the movement and damage and provided any immediate remedial works or temporary works to maintain integrity and safety as far as practicable, proper research and investigation as necessary should be undertaken to fully assess the problem.
Initial appraisal advice
Following and in conjunction with initial research and investigation and appraisal we would normally meet with client, discuss and provide advice first hand, subsequently and dependent on our findings and instructions, provide a brief letter (typically one page – two pages), or a brief extended letter or report setting out the main points discussed (typically three – ten pages). This may include:
• Reference to the letter of instructions brief, and or a brief and reasons for the extended letter or report
• General description of the building or structure
• The extent of movement and associated damage
• The related structure and implications generally
• Initial advice and opinion upon cause/s of movement and associated damage
• Further research and investigations including monitoring of any movement necessary
• Remedial measures and or need for temporary support
• Insurance and appropriateness of making a claim
• Summary, way forward and proposed course of action
Investigation
Subsidence investigation will often involve accurate monitoring of the building or structure movement.
Proper research and investigation of the ground and foundations conditions should be undertaken.
This should include detailed research and investigation with trial pits to expose foundations and adjacent ground and boreholes to ascertain the ground and soil parameters and ground water conditions as far as practicable.
Investigation would normally include such exploratory and opening up works of the existing building construction or structure, necessary to have a proper understanding of the structure and its sensitivity to foundation movement and vulnerability to associated damage.
Report following investigations
Following completion of research and investigations we would normally provide an appropriately well detailed report. This would include:
• Synopsis
• Brief and instructions received
• General description of the building or structure
• The extent of movement and associated damage
• The related structure and implications generally
• Investigations undertaken
• Detailed advice and opinion upon cause/s of movement and associated damage
• Likelihood of further movement and damage
• Any further research and investigation necessary
• Remedial measures required with options as appropriate
• Insurance
• Approvals required including party wall agreement where remedial works might affect adjoining properties
• Summary, way forward and proposed course of action
Remedial Measures
Having conducted sufficient research and investigation to enable appropriate decisions to made we would then make proposals and provide advice in respect of appropriate remedial measures, normally in the form of our Report following investigations.
Underpinning – foundation stabilisation
Underpinning may take various forms from more traditional mass concrete underpinning, concrete pad and reinforced concrete beams or slabs to piled underpinning or other more specialist techniques. Each case should be fully considered and the form of underpinning decided on its merits.
Remedial works – design and control
Having ascertained and agreed the scope or remedial works required we can design the appropriate remedial scheme and prepare all necessary drawings, specifications, tender and contract documents.
On large projects we can provide on site control with site inspections carried out by our resident engineer.
On most small scale or domestic remedial projects, for economic reasons it is unlikely a resident engineer will be used and site control will usually be limited to appropriate site inspections at key stages and or when valuation inspections are undertaken.
Insurance claims
We have considerable experience and regularly advise property owners, Insurers, Insurers appointed loss adjusters and the Insured regarding technical and engineering aspects of building or structure damage and or subsidence claims.
We can advise upon all aspects of insurance claims within our expertise as consulting structural engineers.
Dangerous and unsafe structure investigation, remedial design and control
The practice has developed expertise in investigation, design and provision of temporary and permanent works for dangerous or unsafe structures.
Andrew Dust has considerable experience dealing with dangerous structures and related legal issues.
We provide professional advice and designs in respect of:
Temporary Works design
Temporary works for structures
Temporary works for foundations and groundworks