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PLAXIS 2D Version 9.0 purchased
In order to be able to provide the very latest in
sophisticated finite element analysis (FEA) to our clients we have recently
invested in a licence for
PLAXIS 2D
version 9.0. PLAXIS is widely regarded in the geotechnical industry as
the state of the art software for numerical modelling of soil behaviour and soil
structure interaction.
PLAXIS has the ability to use a wide range of
constitutive models from the simple Mohr Coulomb model for
routine analysis to a range of sophisticated models including a soft soil creep
model which allows the time-dependent and logarithmic compression
behavior of normally consolidated soft soils to be simulated.
In addition PLAXIS allows steady state seepage analysis of ground water flow to
be determined and for special applications we are able carry out transient
modelling of ground water flow using the
PLAXFLOW
extension to PLAXIS.
As part of our investment in our advanced numerical modelling
capability we are working with WILDE FEA,
the UK distributor of PLAXIS, to become one of their associate partners allowing
our experience using PLAXIS to be shared with other users and encouraging the
wider use of FEA in geotechnical design.
Whilst an extremely powerful tool capable of sophisticated
analysis, simple models can be set up as quickly as with any other geotechnical
software. This allows us with a single computer model to determine safe
bearing pressures, stable slope angles, ground settlement, and the stresses
imposed upon structures. The consequence for our clients is reduced design
costs, less conservatism in design and ultimately a more economical product.
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Chalk Mine Stabilisation Presentations
Chris and John in conjunction with Andrew O'Donovan of
Ritchies are
undertaking a series of presentations describing the mine stabilisation works carried out at
Briars Lane in Hatfield. The first presentation was given to the Yorkshire
Regional Geotechnical Group of the ICE on 15th October 2008 and was a great
success with positive feedback from attendees and a range of probing questions.
All events are free and we hope you can join us at one of the
future presentations. All presentations start at 6pm with a light buffet
and the dates and locations are as follows, if
you are interested in attending please contact us for more details.
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| 21st January 2009 |
ICE Kent and East Sussex
Branch Geotechnical Group, Best Western, Maidstone, Kent |
| 28th January 2009 |
Thames Valley
Regional Group of the ICE, Holiday Inn, Guildford |
| 9th March 2009 |
East Midlands Geotechnical Group, Loughborough University |
| 21st April 2009 |
Western Regional
Group of the Geological Society, Bristol University |
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| Southborough
Embankment, Tonbridge RJM is providing
geotechnical support for the stabilisation of a
failing railway embankment. Having completed a desk study of the site an
initial phase of ground investigation was specified and supervised.
Careful examination of soil samples during this
investigation identified a significant thickness of soliflucted material.
As a result a deep stabilisation solution was required and
subsequently a second phase of investigation comprising rotary boreholes was
carried out. Due to access difficulties Ritchies' Sherpa slope climbing rig
was used in conjunction with a rotary head - the first time that this
arrangement had been used in the UK. |
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Devil's
Bridge, Chapeltown
RJM is providing
geotechnical support for the design of a new dam to attenuate storm flows
entering a business park to the north of Sheffield. Following a
detailed desk study it was identified that the site had a considerable
legacy of coal and ironstone mining beneath it which posed a significant
risk to construction. A multi purpose ground investigation was
specified to address the mining risk, determine the stratigraphy and obtain
soil and rock design design parameters. In addition in situ packer (lugeon)
testing was carried out to determine the soil and rock permeabilities.
This scheme is now moving towards detailed design in which RJM will be
carrying out detailed seepage and stability analyses of the dam using finite
element analysis software to determine the depth of cut off and dam cross
section required. |
| Blea Moor,
Ribblehead RJM has provided
geotechnical support in the investigation and design of remedial slope
stabilisation measures for a railway rock cutting at the eastern entrance to
Blea Moor tunnel. Due to access difficulties investigation was limited
to examination of rock exposures and hand dug pitting. The
stabilisation solution involved a combination of crest drainage, face
netting, spot bolting and scaling. RJM provided site supervision to
control the extent of the scaling and bolting works and supervise the
testing of and installation of the mesh and associated support system.
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Broken Brae, Richmond
RJM has been working closely with developers to secure
planning permission for a new ecological holiday park located on the
northern banks of the River Swale. The proposed development is sited below the 100 year flood level of the adjacent river and RJM were
asked to assess the condition of the existing flood defences and provide
advice on any remedial measures necessary. Following an initial walk over survey an intrusive ground
investigation was carried using the services of our
partner company
Drift Ground Investigation. The results of this study were then used to
advise on the remedial measures necessary for the flood defences to
provide adequate protection against the design flood event. In
addition the results of the investigation were used to provide foundation
advice for the proposed lodges and the substantial earthworks operations
proposed.
Close liaison was maintained with the Environment Agency throughout the
scheme in order to ensure the information required for their approval was
obtained. |
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Briars Lane, Hatfield
RJM have been working closely with both
the client and contractor Ritchies on a £2.65M chalk mine infilling scheme in
Hatfield. The site was mined up until the early part of last century
and surface subsidence has subsequently caused numerous problems to
structures across the site including surface collapse adjacent to a single
storey bungalow during the late 1990's. The scheme is the first time that
stabilisation of partially collapsed chalk mines has been undertaken in the
UK and has presented a number of challenges. RJM have been
engaged as technical specialists to ensure an effective treatment
methodology is developed. The relatively straightforward process of
bulk infilling open voids has been carried out using foamed concrete.
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A more sophisticated process is required for treating the collapsed
workings. This is being carried out through ascending stage injection
of a thick grout under high pressure to both compact loose ground and infill
small voids. Due to the novel nature of the
ground treatment being carried out a high level of control and monitoring is
being applied to the works. RJM have been
engaged to develop a 3D ground model using Rockworks software into
which all the historical ground investigation data has been input. As
the works progress ongoing grouting and validation probing data is being
added to the 3D ground model. This visualisation tool is proving
invaluable in monitoring the progress and efficacy of the works as they
progress. |
