7 th eptember 2015 Lindenmoss Limited C/O Pump Court Tax Chamber 16 Bedford Row London WC1R 4EF 7-11 Harding treet, Leicester, LE1 4DH Tel: 0116 2536333 Fax. 0116 2514709 Email: geotechnical@nicholls-colton.co.uk Website: www.nicholls-colton.co.uk For the attention of Mr. teve Young (enior Planning Consultant), Pro Vision Planning & Design (Working for and on behalf of Lindenmoss Ltd). Dear irs, Re: G15065 Gynsill Court, Gysill Lane, Anstey, Leicestershire. We are pleased to summarise the findings of our recent additional investigation works for the above named site. We comment as follows: An interpretative ground investigation report was issued by Nicholls Colton Geotechnical (NCG) in May 2015 (ref G15065). This report identified that foundations for the proposed new housing at the site would be likely to require deepening due to the presence of trees and localised areas of softened soils at the site, in addition an area was identified on the western boundary where granular soils (sands) are present, the relative density of which was unknown (and hence it was not possible to confirm the appropriate foundation solution). The purpose of this additional investigation was to determine the extent of the area where the foundations would need to deepened (due to trees and softened soils) and determine the relative density of the granular soils encountered on the western side of the site. Four 150mm diameter cable percussion boreholes were put down at the site, to depths in the range 4.45m to 10.00m below existing ground level. The borehole logs and an exploratory hole location plan (NCG drawing no. G15065A-IR/03) are attached. A detailed assessment of the extent to which trees affect the foundations has been undertaken in accordance with NHBC guidelines. The tree survey and topographical plan were provided (by the client). Each tree was assessed individually then plotted onto a combined plan. The extent of the softened soils has also been plotted onto the plan. The plan showing the minimum depth required for foundations of the proposed new buildings is attached (Nicholls Colton Geotechnical drawing no. G15065A-IR/04). The outline of the proposed new housing layout has also been superimposed. The boreholes have proven the depth of the softened soils and the relative density of the granular soils present on the north-western boundary. It has been determined that the granular soils (where encountered) are of loose relative density to approximately m and the cohesive soils are of soft consistency to a similar depth. Therefore, the foundations of any new buildings in this area will need to be taken to depths in order of m below existing ground level; to found upon the firmer cohesive soils and/or the medium dense granular soils. Given the marginal nature of the soils in this area, it is recommended that the founding strata of buildings in this area are inspected by a suitably experienced engineer (prior to pouring concrete). JP/G15065-01 NICHOLL COLTON GROUP LTD Head Office: 7-11 Harding treet, Leicester LE1 4DH. Tel: 0116 253 6333 Fax: 0116 251 4709 Registered in England No. 05605955
Given the topography of the site (and taking into account the desk study), it is considered that the soils along the north-western boundary have been softened by the adjacent flood zone and hence is only localised to the lower extremity of the site. Where deepened foundations are required (in particular along the north-western boundary); consideration will be required with regard to the stability of the excavations. As noted in the original report, the soils are locally granular and water bearing, which may lead to instability and potential collapses of the foundation excavations. Based on the current housing layout, taking into account the issues of stability and given the number of plots which are likely to require deepened foundations (greater than m), some consideration should be given to the adoption of a piled foundation solution for the affected plots. Consideration should be given to the type of pile adopted; however, it is likely that the use of a driven pile may be more favourable for the ground conditions encountered. The advice of a specialist contractor should be sought in this respect. As an initial guide, for isolated concrete piles of 200mm square, penetrating 12m into the ground, allowable pile loads of approximately 300-350kN should be appropriate, using a factor of safety of 2.5. The actual safe working load of individual piles will be dependent upon the type of pile adopted and the method of installation adopted. It is recommended that selected piles are tested for loads up to 1.5 times the working load in accordance with the ICE pecification for Piling and Embedded Retaining Walls: 1996. Alternatively, it may prove more economically viable to re-design the housing layout, to avoid the areas requiring foundations to be taken deeper than say m. We trust that the above is satisfactory. hould you have any further queries whatsoever, please do not hesitate to contact the writer. Yours faithfully, J.W. Poynton Geo-Environmental Engineer NICHOLL COLTON GEOTECHNICAL JP/G15065-01
Client Lindenmoss Limited. ite Gynsill Court, Gysill Lane, Anstey, Leicester. Boring diameter: 150 mm to 10.00m BOREHOLE RECORD - BH1 (Cable Percussion) Casing diameter: Project No.: G15065 Logged by: Ref: D1 D3 D4 D6 CA amples & In situ Tests Depth (m) 0.20- -1.65 1.70- -2.45 Ground Level: PT N N=10 N=13 Water 25/06/2015 Location: cale: Level Depth Legend (maod) (m) trata Description 0.20 TOPOIL. Firm orange-brown and grey slightly sandy slightly gravelly CLAY with some roots and rootlets. Gravel is fine to coarse angular to sub-rounded quartz and sandstone. Firm red-brown slightly sandy slightly gravelly CLAY with some roots and rootlets. Gravel is fine to coarse angular to sub-rounded quartz, siltstone and sandstone. - 1:55 Backfill D7 2.50- D9-3.45 N=14 D10 D12 3.50-4.00 4.00 4.00-4.45 N=37 3.50 Dense pale grey fine to medium AND with many weakly cemented sandstone fragments. D13 D15 D16 4.50-5.00 5.00 5.00-5.45 5.50-6.50 N=35 4.50 5.00 (Dense) greenish grey silty fine to medium AND with many weakly cemented sandstone fragments. (Density based on drillers description / ease of drilling). tiff friable red-brown silty CLAY. D18 6.50 6.50-6.95 N=40... becoming very stiff below 6.50m. D20 8.00 8.00-8.40 50/290mm D22 9.50 9.50-9.90 50/285mm 10.00 Remarks and Water Observations 1. Hand dug starter pit to m. 2. No groundwater seepages were encountered during boring operations. 3. Borehole backfilled with arisings upon completion. End of Borehole at 10.00 m heet 1 of 1
Client Lindenmoss Limited. ite Gynsill Court, Gysill Lane, Anstey, Leicester. Boring diameter: 150 mm to 4.45m BOREHOLE RECORD - BH2 (Cable Percussion) Casing diameter: Project No.: G15065 Logged by: CA Ground Level: amples & In situ Tests Water Ref: Depth (m) PT N D1 0.40-25/06/2015 Location: cale: Level Depth Legend (maod) (m) trata Description 0.40 TOPOIL. Firm orange-brown slightly sandy CLAY with occasional rootlets. - 1:55 Backfill D3 D4-1.65 1.70- N=4 oft orange-brown slightly sandy CLAY with occasional rootlets. D6 D7-2.45 2.50- N=9 Firm brown and grey slightly sandy slightly gravelly CLAY. Gravel is fine to coarse angular to sub-rounded sandstone and siltstone. D9-3.45 N=24 Medium dense pale grey fine to medium AND with many weakly cemented sandstone fragments. D11 4.00 4.00-4.45 N=36... becoming dense below 4.00m. 4.45 End of Borehole at 4.45 m Remarks and Water Observations 1. Hand dug starter pit to m. 2. No groundwater seepages were encountered during boring operations. 3. Borehole backfilled with arisings upon completion. heet 1 of 1
Client Lindenmoss Limited. ite Gynsill Court, Gysill Lane, Anstey, Leicester. Boring diameter: 150 mm to 5.45m BOREHOLE RECORD - BH3 (Cable Percussion) Casing diameter: Project No.: G15065 Logged by: Ref: D1 D2 D4 D5 D7 D8 D10 D11 D13 D14 D16 CA amples & In situ Tests Depth (m) 0.35-0.95 0.95- -1.65 1.70- -2.45 2.50- -3.45 3.55-4.00 4.00 4.00-4.45 4.50-5.00 5.00 5.00-5.45 Ground Level: PT N N=5 N=9 N=7 N=13 N=40 Water 25/06/2015-26/06/2015 Location: cale: Level Depth Legend (maod) (m) trata Description 0.35 0.95 1.35 2.30 3.40 3.55 5.45 TOPOIL. oft orange-brown and grey silty slightly sandy CLAY with occasional rootlets. Gravel is fine to coarse angular to sub-rounded sandstone. Loose orange-brown and grey clayey silty gravelly fine to coarse AND with occasional rootlets. Gravel is fine to coarse angular to sub-rounded quartz and sandstone. oft red-brown speckled black sandy slightly gravelly CLAY. Gravel is fine to coarse angular to sub-rounded sandstone and quartz. Loose orange-brown fine to coarse AND and fine to coarse sub-angular to sub-rounded quartz GRAVEL. oft orange-brown sandy slightly gravelly CLAY. Gravel is fine to coarse angular to sub-rounded sandstone and quartz. oft red-brown and grey silty CLAY. Firm red-brown and light grey CLAY with some siltstone bands.... becoming stiff below 5.00m. End of Borehole at 5.45 m - 1:55 Backfill Remarks and Water Observations 1. Hand dug starter pit to m. 2. Groundwater formed to level of 3.05m at end of hole. 3. Borehole backfilled with arisings upon completion. heet 1 of 1
Client Lindenmoss Limited. ite Gynsill Court, Gysill Lane, Anstey, Leicester. Boring diameter: 150 mm to 3.45m BOREHOLE RECORD - BH4 (Cable Percussion) Casing diameter: Project No.: G15065 Logged by: Ref: D1 D2 D4 D5 D7 CA amples & In situ Tests Depth (m) 0.20-0.80 0.80- -1.65 1.70- -2.45 Ground Level: PT N N=5 N=10 Water 26/06/2015 Location: cale: Level Depth Legend (maod) (m) trata Description 0.20 0.80 1.30 TOPOIL. tiff orange-brown slightly sandy CLAY with occasional rootlets. Firm locally soft orange-brown slightly sandy CLAY with occasional rootlets. Firm orange-brown and grey slightly sandy slightly gravelly CLAY. Gravel is fine to coarse angular to sub-rounded quartz and sandstone.... becoming stiff below m. - 1:55 Backfill D8 D10 2.80- -3.45 N=37 2.80 3.10 3.45 tiff friable red-brown silty CLAY. Dense pale grey fine to medium AND with many weakly cemented sandstone fragments. End of Borehole at 3.45 m Remarks and Water Observations 1. Hand dug starter pit to m. 2. Groundwater formed to level of 3.05m at end of hole. 3. Borehole backfilled with arisings upon completion. heet 1 of 1
BH3 TP6 BH2 BH1 TP8 BH4 TP7 N Based upon Clients Drawing Key: - Trial Pit (TP) Location - Borehole (BH) Location TP5 TP3 TP2 TP4 TP1 Client: Lindenmoss Limited Project: Gynsill Court, Gysill Lane, Anstey, Leicester. Title: Exploratory Hole Location Plan Not to cale ept 2015 Drawing No. G15065A-IR/03