With the computer program BISAR the stresses and strains are determined.

Transcription

1 Sil Piling Mats With a large number f prjects in the UK requiring the cnstructin f piling mats and requests fr RadCem stabilised sil design infrmatin, we have made a general table fr the thickness f this type f cnstructin fr different sil types. Due t the fact that the type f vehicles during the lifetime f this cnstructin is n all the sites practically the same: pilling drilling machines and trucks, that are delivering the piles. Based n the Bearing Capacity an estimatin f the type f sil is made and a mix design is estimated and the mechanical prperties f the stabilizatin (1). These mix designs are indicative, and might need t change if lcal circumstances are requiring this (large amunts f rganic material in sil). Fr the calculatin f the bending mments, strains under the tires f the trucks (2) the multi-layer elastic methdlgy is used. With the cmputer prgram BISAR the stresses and strains are determined. Fr the calculatins fr the minimum thickness f the pilling drilling machines (3), the Hetenyimethd was used. With this methd the bending mment, and the shear strength can be accurately determined under the specific cntinuus tracks f the pilling drilling machines.

2 1. Mix Designs and mechanical prperties f the stabilized material. Sub grade Mdulus f subgrade reactin Sil type RadCem Cement Stiffness Breaking strain [E dyn : MPa] [N/mm 3 ] [kg/m 3 ] [kg/m 3 ] [E dyn: MPa] [mm/m] Flexural strength 2. Calculatin f the stresses and strains fr the heavy truck that are delivering the piles. Fr the calculatin we assumed a standard axle lad f 100 kn, with 4 wheels per axle. Shear strength 20 0,020 Clay 2, ,75 0, ,025 Clay 2, ,90 0, ,030 Clay 2, ,05 0, ,035 Clay 2, ,20 0, ,040 Sandy clay 1, ,35 0, ,045 Sandy clay 1, ,35 0, ,050 Sandy clay 1, ,35 0, ,055 Sand 1, ,50 1, ,060 Sand 1, ,50 1, ,065 Sand 1, ,50 1, ,080 Sandy gravel 1, ,65 1, ,085 Sandy gravel 1, ,65 1, ,090 Sandy gravel 1, ,65 1, ,095 Sandy gravel 1, ,65 1,10 PROPERTIES DESIGN Sub grade Mdulus f subgrade reactin Sil type RadCem Cement Stiffness Minimum Thickness Strain [E dyn : MPa] [N/mm 3 ] [kg/m 3 ] [kg/m 3 ] [E dyn: MPa] [cm] [mm/m] 20 0,020 Clay 2, , ,025 Clay 2, , ,030 Clay 2, , ,035 Clay , ,040 Sandy clay 1, , ,045 Sandy clay 1, , ,050 Sandy clay 1, , ,055 Sand 1, , ,060 Sand 1, , ,065 Sand 1, , ,080 Sandy gravel 1, , ,085 Sandy gravel 1, , ,090 Sandy gravel 1, , ,095 Sandy gravel 1, ,12 Safety factr

3 3. Calculatin f the stresses and strains fr the pilling drilling machine. Fr the drilling machine the fllwing assumptins are made: Type f drilling machine: Wltman THW 4017 Weight 40 tn Tracks 900 x 4850mm PROPERTIES DESIGN Mdulus f subgrade reactin Sil type RadCem Cement Stiffness Thickness Flexural strength. shear Sub grade [E dyn: MPa] [N/mm 3 ] [kg/m 3 ] [kg/m 3 ] [Edyn: MPa] [cm] Stress [MPa] safety factr Stress [MPa] 20 0,020 Clay 2, ,69 1,09 0,10 5, ,025 Clay 2, ,92 0,98 0,12 5, ,030 Clay 2, ,99 1,06 0,15 4, ,035 Clay 2, ,19 1,01 0,18 4, ,040 Sandy clay 1, ,18 1,14 0,18 5, ,045 Sandy clay 1, ,31 1,03 0,21 4, ,050 Sandy clay 1, ,25 1,08 0,21 4, ,055 Sand 1, ,48 1,01 0,27 3, ,060 Sand 1, ,42 1,06 0,27 3, ,065 Sand 1, ,37 1,09 0,27 3, ,080 Sandy gravel 1, ,52 1,09 0,36 3, ,085 Sandy gravel 1, ,47 1,12 0,36 3, ,090 Sandy gravel 1, ,43 1,15 0,36 3, ,095 Sandy gravel 1, ,39 1,19 0,36 3,06 safety factr

4 Whilst PwerCem nly started ur business in the UK quite recently we have been able t learn frm the many PwerCem applicatins carried ut abrad ver the last ten years. RadCem sil stabilisatin technlgy enables any materials including rganic tp sils t be effectively stabilised t build strng, safe piling mats fr bth driven and auger piles. With this prven time and cst saving technlgy nw available in the UK. Why is stne and crushed cncrete still being trucked t new sites fr piling mat cnstructin? Have yu had any f the fllwing prblems with a stne piling mat? Planning and lcal issues with the trucking f large amunts f materials t and frm yur site. Miscalculatins with quantities f cut and fill. Levels issues as the weak sub sils cmpact under the heavy stne mat. Mats that need t be far larger than the piling area t allw fr the prblems f shear. Dangers f mving tp heavy rigs nt and ff the unbund stne mat, at cmmencement and end f peratins. Dangers f mving tp heavy rigs arund the unbund stne mat. Unpredictability and delays when setting up the rig fr each pile n the unbund stne mat. Deflectin f the piles due t hard and sft areas/pieces f stne. Heavy rains causing the stne fines t migrate lwer in the mat, allwing the larger stnes n the tp t mve. Frst getting int trapped water in the mat. Piles snagging in the supprting gegrid/mat. Prblems remving the stne and pierced gegrid/mat frm between the piles is time cnsuming and labur intensive. All used stne and gegrid remved after piling must be trucked ff site, as waste These materials used are nw classed as cntaminated and must be landfilled r recycled (cleaned). Bth cstly ptins. It has been shwn that mst piling mats can be cnstructed frm materials already in-situ n yur site. RadCem can be used t prduce predictable, safe mats, with visc static prperties which absrb dynamic impact preventing cracking and breakaway during piling, enabling quick rig set setup and deflectin free piling. RadCem mats are shear resistant, allwing smaller mats t be used, they are als impermeable t water, il and acids enabling planned cllectin f run ff f spills r heavy rain. They are als frst resistant and can be cnstructed and used in all weathers. Finally when the piling is cmplete they can be left in place as blinding fr fundatin cmpnents. Or milled back t sil fr reuse elsewhere n the site. Certified stabilised sil piling mat designs can be prepared by ur clleagues Rdgers Leask cnsulting engineers f Derby.

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