Home Page - Andrew Dust Structural Engineers    
Offices located in:
Telephone: 020 7700 5533
 


Geoechnical Engineering Services


We provide professional advice and designs in respect of all geotechnical aspects of ground works and for all building or structure types, from state of the art to historic buildings.

Our projects range from small below ground drainage or retaining wall schemes through subsidence, ground and foundation movement investigation, to detailed analysis and design of groundworks or foundations for major projects and multi-storey buildings.

Our design expertise encompasses all conventionally adopted materials using recognised and advanced techniques.

We regularly analyse and design foundations, piling, retaining walls, slopes, embankments, ground anchors, temporary works and below ground drainage schemes.

Designs of more complex building and ground structures are undertaken, including earthquake design and ground anchored systems.

Dynamic analysis and design of more dynamically sensitive or critical structures can be undertaken.

Design is fully supported with computer structural analysis design aids and tools, including finite element model and space frame model structural analysis.

Design and drawing is output using CAD facilities.

We value highly and ensure development of a close working relationship with the client, Structural Engineers and other design professionals.

We outline a brief summary of those geotechnical engineering activities we undertake, these include:

· Foundation and ground investigation
· Investigation of ground, ground structure and or foundation movement
· Precision monitoring of ground, ground structure and or foundation movement
· Detailed assessment and analysis of foundation movement and settlement including, immediate, long term and or consolidation settlement, differential movement.
· Design and analysis of:
o Foundations
o Underpinning and foundation stabilisation
o Piling
o Foundations and structures against clay soil movement, heave and settlement.
o Special or deep foundations
o Deep basements and water retaining construction
· Earth retaining structures and retaining walls including:
o Mass concrete gravity
o Reinforced concrete
o Masonry
o Reinforced masonry
o Ground anchored
o Soil nailing
o Reinforced earth
o Structural steel sheeting
o Piling
o Timber
· Slopes and embankments including:
o Un-reinforced slopes
o Ground anchored
o Soil nailing
o Reinforced earth
· Dynamic and earthquake design

Foundation and Ground Investigation

Please refer to Structural Engineering - Ground and foundation investigation and other related sections, these include: Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design

Investigation of ground, ground structure and/or foundation movement

Please refer to Structural Engineering - Ground and foundation investigation and other related sections, these include: Surveys, appraisals, structural investigation, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design

Precision monitoring of ground, ground structure and/or foundation movement

Monitoring of structures, foundations and adjacent or supporting ground may form part of a proper investigation to determine the risk to safety and structural integrity, causes of movement and appropriate remedial works and course of action. We regularly conduct simple and or precision monitoring investigations.
PC controlled level and tilt monitoring of structures can be adopted in more sensitive or critical structures e.g. historic or structurally suspect structures.

Site investigation for retaining walls, slopes, embankments and anchorage systems should ensure the ground conditions and foundations of any adjacent buildings or structures are properly assessed in the immediate vicinity and within the zone of influence or behaviour of the ground structure. This can involve investigation some distance away from the structure and accurate monitoring of any movement.

Please refer to Structural Engineering - Ground and foundation investigation and other related sections, these include: Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design

Detailed assessment and analysis of ground and foundation movement and settlement

Settlement of ground subject to changes in stress and consequently of foundations, in this case piles may be separated into two principal parts, immediate and consolidation settlement.
Immediate settlement being due to deformation of the soil structure without change in water content, the rate of settlement being rapid and taking place during application of the loading.
Consolidation settlement being due to loss of soil volume due to a reduction in groundwater, migrating under stress.

We regularly are engaged and can provide a detailed analysis and assessment of ground and foundation movement and settlement.

Ground and associated foundation or structure movement, immediate and long term, may be appropriately modelled using recognised predictive methods and analysed with spreadsheet software. Or alternatively, when circumstances warrant, adopting more advanced analysis techniques, including finite element modelling.

In clays soils, London Clay for example, analysis and assessment of immediate settlement is likely to be assessed using Terzaghi, Butler and Fox modified approach.
Long term extent and rate of consolidation settlement is likely to be assessed using a Skempton and Bjerrum modification of Terzaghi's theory of consolidation and Fox modified approach.

Complex problems including various aspects of ground movement can be assessed these include:

· Varying soil and ground conditions
· Settlement of deep and piled foundations
· Differential settlement and movement
· Ground swelling, heave and or recovery
· Ground movements associated with changes in groundwater regime
· Ground movements associated with excavations
· Ground movements associated with retaining walls and earth supporting structures
· Ground movements associated with ground anchored supporting structures
· Movement and instability of slopes
· Clay soil movement - shrinkage and settlement, heave and uplift
· Groundwater flow

Please refer to Structural Engineering - Ground and foundation investigation and other related sections, these include: Building and Structure design, Foundation design, Refurbishment and conservation design, Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design

Design and Analysis

Foundations

Please refer to Structural Engineering and other related sections, these include: Building and Structure design, Refurbishment and conservation design, Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design, Ground and Foundation investigation.

Underpinning and foundation stabilisation

Please refer to Structural Engineering - Subsidence investigation, remedial design and control, Underpinning and foundation stabilisation and other related sections, these include: Foundation design, Building and Structure design, Refurbishment and conservation design, Surveys, appraisals, structural investigation and reports, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design, Ground and Foundation investigation.

Piling

Design of piled foundations and structural schemes for the full spectrum of buildings and structures is undertaken including low rise to multi storey structures and earth supporting structures

We have expertise of design of piling within difficult ground or with special design requirements.

We can provide a complete design and analysis service to clients, design and construction companies and piling contractors.

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 piling design.
We regularly commission and control foundation and ground investigation.
Please refer to Ground and Foundation investigation and reports.

In addition to more straightforward piling designs, more specialist piling scheme designs and analysis are undertaken, these include:

· Small diameter bored and driven piles
· Large diameter bored and driven piles
· Undereamed bored piles
· CFA piles
· Tension or anchor piles
· Immediate and long term settlement and uplift analysis of bored and driven piled foundations
· Piling schemes and foundations within shrinkable clays soils, e.g. London or Oxford Clay.
· Piling schemes and foundations within chalk and in particular where chalk solution features are prevalent.
· Piling schemes with foundation bridge or cantilever transfer structures, perhaps to avoid undue loading upon ground services or existing foundations etc.
· Piled foundations designed for dynamically sensitive or critical structures.
· Piling schemes for underpinning or other foundation stabilisation or improvement works
· Piling for retaining walls, earth supporting and or ground anchored schemes.
· Piling in close proximity to existing buildings, structures, tunnels services
· Restricted access piling
· Piling for temporary works

Piling designs may be carried out in accordance with the relevant recommendations of:

· BS 8004: 1986 Code of Practice for Foundations
· BS 6031: 1981 Code of Practice for Earthworks
· BS 8002: 1994 Code of Practice for Earth Retaining Structures
· BS 8006: 1995 Code of Practice for strengthened/reinforced soils and other fills
· BS 8081: 1989 Code of Practice for ground anchorages
· EN 1997: Eurocode 7 Geotechnical

Please refer to other related sections, these include: Structural Engineering - Building and Structure design, Foundation design, Refurbishment and conservation design, Surveys, appraisals, structural investigation and reports, ground and foundation investigation, Subsidence investigation, remedial design and control, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design

Foundations and structures against clay soil movement, heave and settlement

Please refer to Structural Engineering - Subsidence investigation, remedial design and control, Underpinning and foundation stabilisation and other related sections, these include: Foundation design, Piling, Building and Structure design, Refurbishment and conservation design, Temporary Works Design, Ground and Foundation investigation and reports

Special or deep foundations

We have expertise of design of foundations within difficult ground or with special design requirements including deep foundations.

Special foundations would include those with made or poor ground, for heavy structures or for dynamically sensitive structures.

Deep foundations would include foundations for buildings with deep basements, requiring deep foundations to competent ground and or piled foundations.

Careful design and assessment of load carrying capacities, extent of ground movements, affect upon adjacent buildings and structures is important.

Health and safety issues are paramount and the need for proper safeguards and temporary support during excavation and construction is important

Please refer to Structural Engineering - Foundation design, Piling, Detailed assessment and analysis of ground and foundation movement and settlement and other related sections, these include: Building and Structure design, Refurbishment and conservation design, Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design, Ground and Foundation investigation.

Deep basement and water retaining construction

We have expertise of design of deep basement and water retaining construction.

These may be deep basement and water retaining construction in new or within existing or adjacent to existing buildings and structures.

Health and safety issues are paramount and the need for proper safeguards and temporary support during excavation and construction is important

Careful design and assessment of the extent of ground movements and affect upon adjacent buildings and structures during construction and measures for preventing or effectively dealing with groundwater ingress is important.

Our design expertise encompasses all conventionally adopted materials using recognised and advanced techniques.

We typically design basements or water retaining structures of Type A: damp tanking protection or Type B: - integral protection or Type C: drained protection, generally adopting masonry or reinforced concrete construction.

Deep basement and water retaining construction designs may be carried out in accordance with the relevant recommendations of:

· BS 8102: 1990 Code of Practice for Protection of Structures Against Water from the Ground
· BS 8007: Code of Practice for design of concrete structures for retaining aqueous liquids
· BS 8215: 1991 Code of Practice for Design and Installation of Damp Proof Courses in Masonry Construction
· BS 8004: 1986 Code of Practice for Foundations
· BS 6031: 1981 Code of Practice for Earthworks
· BS 8002: 1994 Code of Practice for Earth Retaining Structures
· EN 1997: Eurocode 7 Geotechnical

Please refer to Structural Engineering - Foundation design, Piling, Detailed assessment and analysis of ground and foundation movement and settlement and other related sections, these include: Building and Structure design, Refurbishment and conservation design, Temporary Works Design, Ground and Foundation investigation

Earth Retaining Walls

We have considerable expertise in the analysis and design of earth retaining structures and retaining walls.

These may be new earth retaining structures and retaining walls or within existing or adjacent to existing buildings and structures.

Health and safety issues are paramount and the need for proper safeguards and temporary support during excavation and construction is important

Careful design and assessment of the extent of ground movements and affect upon adjacent buildings and structures during construction and measures for effectively dealing with groundwater is important.

Designs are typically carried out in accordance with the respective material codes of practice and the relevant recommendations of:

· BS 8002: 1994 Code of Practice for Earth Retaining Structures
· BS 8006: 1995 Code of Practice for strengthened/reinforced soils and other fills
· BS 8081: 1989 Code of Practice for ground anchorages
· BS 8004: 1986 Code of Practice for Foundations
· BS 6031: 1981 Code of Practice for Earthworks
· EN 1997: Eurocode 7 Geotechnical

Our design expertise for earth retaining structures and retaining walls encompasses all conventionally adopted materials using recognised and advanced techniques including:

4.7.1 Mass concrete gravity
4.7.2 Reinforced concrete
4.7.3 Masonry
4.7.4 Reinforced masonry
4.7.5 Ground anchored
4.7.6 Soil nailing
4.7.7 Reinforced earth
4.7.8 Structural steel sheeting
4.7.9 Piling
4.7.10 Timber

Please refer to Structural Engineering - Foundation design, Piling, Detailed assessment and analysis of ground and foundation movement and settlement and other related sections, these include: Building and Structure design, Refurbishment and conservation design, Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design, Ground and Foundation investigation

Slopes and embankments:

Ground slopes and embankments including those particular types and applications listed below are analysed and or designed using various available methods.
We have considerable expertise in the analysis and design of ground slopes and embankments.

These may be new or existing ground slopes and embankments, remote or adjacent to existing buildings and structures.

Health and safety issues are paramount and the need for proper safeguards and temporary support during any excavation and or construction is important

Careful design and assessment of the extent of ground movements and affect upon adjacent buildings and structures during construction and measures for effectively dealing with groundwater is important.

Designs may be carried out in accordance with the respective material codes of practice and the relevant recommendations of:

· BS 6031: 1981 Code of Practice for Earthworks
· BS 8006: 1995 Code of Practice for strengthened/reinforced soils and other fills
· BS 8081: 1989 Code of Practice for ground anchorages
· BS 8002: 1994 Code of Practice for Earth Retaining Structures
· BS 8004: 1986 Code of Practice for Foundations
· EN 1997: Eurocode 7 Geotechnical

Our design expertise for ground slopes and embankments, including those particular types and applications listed below, encompass all ground conditions and types and conventionally adopted materials using recognised and advanced techniques:

4.8.1 UN-reinforced slopes
4.8.2 Ground anchored
4.8.3 Soil nailing
4.8.4 Reinforced earth

Please refer to earth retaining structures and retaining walls, detailed assessment and analysis of ground and foundation movement and settlement and other related sections, these include: Structural Engineering - Building and Structure design, Refurbishment and conservation design, foundation design, Surveys, appraisals, structural investigation and reports, Subsidence investigation, Dangerous and unsafe structure investigation, remedial design and control, Temporary Works Design, Ground and foundation investigation.

Andrew Dust

Andrew Dust has specialist knowledge and is very experienced with the analysis, design and construction of earth retaining structures and retaining walls, slopes and embankments.

Andrew Dust has undertaken postgraduate research and studies including:
· City University London: Advanced MSc soil mechanics
· Oxford University: Reinforced Soil: Mechanics and design; Behaviour of soil and reinforcement; soft ground applications; steep slope and wall applications

Andrew Dust would be pleased to help and provide detailed assistance where difficult or special circumstances require.

Dynamic and earthquake design

Dynamic analysis and design of more dynamically sensitive or critical structures can be undertaken.

This can take account of soil properties and soil-structure interaction and model response to dynamic and earthquake input forces, displacements and accelerations.

Whilst design and project management of the design of structures and foundations can be undertaken in house, where the project design criteria or special circumstances apply we are likely to call upon specialist consultants for appropriate dynamic modelling and analysis.