STRUCTURAL CALCULATIONS FOR FOUNDATION AND WALL LATERAL ASSESSMENT AND WALL TIE ASSESSMENT TYPE 4 TYPE A ANCON

Transcription

1 . SureCav CAVITY SPACER SYSTEM STRUCTURAL CALCULATIONS FOR FOUNDATION AND WALL LATERAL ASSESSMENT AND WALL TIE ASSESSMENT TYPE 4 TYPE A ANCON Job No: Mr Charlie Ayers SureCave Ltd Holbrook Lodge Wincanton BA9 8BT May 2009 Ian Caldwell Bsc (Hons) C Eng MICE MI Struct E SureCav Ltd Cavity Spacer System Wall Tie Assessment May

2 Structural Calculations: 1.0 INTRODUCTION 2.0 LOADING 3.0 ASSESSMENT OF LOADING AND PROPOSED TWO STOREY DOMESTIC STRUCTURE FOUNDATION DESIGN 4.0 STABILITY 5.0 WALL LOAD ASSESSMENT 6.0 LATERAL LOAD ASSESSMENT 7.0 WALL TIE ASSESSMENT ANCON TYPE 4 TYPE A 225MM LONG AND TYPE 2 225MM LONG Appendix A: Sketch Details SureCav Ltd Cavity Spacer System Wall Tie Assessment May

3 1.0 INTRODUCTION The following calculations asses the structural calculations and the structural elements and overall stability of cavity wall construction using the SureCav Ltd Cavity Spacer System for proposed two storey domestic dwellings and assessment of proposed foundations to this 125mm random sandstone build external skin and 100mm thick inner dense concrete block and 50mm celotex insulation and 50mm Surcav filler. Design Philosophy: Building Type: Roof Construction: Twostorey domestic proposed houses constructed from load bearing masonry and or timber frame, concrete ground floors. Trussed timber rafters supported on inner leaf of external walls. Floor Construction: Suspended concrete ground floor ( Not Applicable ). Wall Construction: Foundations: Load bearing cavity masonry to all external walls and main cross walls with 100mm thick flint external skin. 500mm wide trench fill mass concrete based on an average of 150kN/m2 for this location in the United Kingdom ref Appendix A. Refer to Appendix A for sketch details SureCav Ltd Cavity Spacer System Wall Tie Assessment May

4 2.0 LOADING BS6399: BS6399: BS6399: BS5628: Dead and imposed loads floor loads Wind Loads Imposed roof loads and snow loads Structural Use of Masonary 2.1 WIND LOAD Location: Basic wind speed Factors Site wind speed: Southern England Vb = 25m/s Sa1, S1,, Ss, Ssp = 21m/s Vs= Vb x Sa Sd Ss Ssp=21m/s Terrain and building factor: Sb = 1.8 Effective wind speed: Ve = Vs x Sb Ve = 21 x 1.8 = 21m/s Dynamic wind pressure at He: qs = x 103 x Ve2 Qs = x 103 x = 1.15kN/m2 and can be 1.5% of dead load for lateral loads 2.2 STATIC LOADS: Tiled Roof: Dead Loads: Tiles = 0.66kN/m2 Felt/Battens = 0.05kN/m2 Rafters = 0.15kN/m2 = 0.8kN/m2 Susp ceilg joist Ceiling board Insulation& services = 0.15kN/m2 = 0.10kN/m2 = 0.05kN/m2 = 0.30kN/m2 Live Loads: Rafters = 0.60kN/m2 = 0.25kN/m2 Total = 1.95kN/m2 Walls: Dead Loads 215mmSolid = 4.0kN/m2 Cavity Wall 100flint = 3.50kN/m2 Blockwork Wall = 1.80kN/m2 Timber Stwk = 0.50kN/m2 Suspended Floors: Dead Loads: Floorboards = 0.15kN/m2 Floor Joists = 0.15kN/M2 Ceiling Board = 0.10kN/m2 = 0.40kN/m2 Live Loads: Floor(domestic) = 1.50kN/m2 SureCav Ltd Cavity Spacer System Wall Tie Assessment May

5 Loading Cont d Total = 1.90kN/m2 Supded Floors Concrete: Dead Loads: Screed = 1.80kN/m2 Concrete 150 beam and block = 2.50kN/m2 Live Loads: Floor (domestic) = 1.5kN/m2 Total = 5.8kN/m2 3.0 ASSESSMENT OF LOADING AND CHECK ON PROPOSED TWO STOREY EXTENSION FOUNDATION DESIGN External wall loading to two storey domestic house with external 100mm flint skin in grade 3 mortar Walls gable = 3 x 3.5 x 2.5 = 27 kn/m Unfactored Floors = 3 X 1.9 = 6 kn/m Unfactored Floors ground = 3 x 5.8 = 18 kn/m Unfactored Roof = 4. x 1.95 = 8 kn/m Unfactored Total = 60 kn/m Load to underside of foundation = 60/150 = < 50mm Please note this is for an 500mm wide foundation and an allowable ground bearing pressure of 150kN/m and typical for this location in the United Kingdom of stiff clays. Note this is subject to site investigation and may require special foundations should poor ground conditions be revealed. PROVIDE 500MM WIDE TRENCH FILL C20 CONCRETE FOUNDATIONS 4.0 STABILITY Stability of all the structures is provided by load bearing masonry walls in each orthogonal direction or timber framing when applicable. SureCav Ltd Cavity Spacer System Wall Tie Assessment May

6 APPENDIX A STRUCTURAL DETAILS SureCav Ltd Cavity Spacer System Wall Tie Assessment May

7 5.0 WALL LOAD ASSESSMENT The Following is a vertical load assessment of the proposed cavity wall at first floor level using 50mm cavity and 125mm thick sand stone and 100mm thick internal skin and assuming isolated 1m load bearing pier is to remain say adjacent to either a door or a window and designed as a column taking two storey gable as the worst case. Note wall above load bearing 300mm thick masonry cavity with external 125mm sand stone external skin 50mm Surecav, 50mm insulation and 100mm thick dense concrete bock inner skin. Blocks in high quality mortar fk = 5.0N/mm2. Loading: Roof Roof span = 8.0m Circa Loading = 4.0 x 1.95 = 8.0 kn/m First floor Floor span = 4.0m circa Loading = 2.0 x 1.90 = 4.0 kn/m Wall Wall ht say at gable = 5.0m circa Loading = 5.0 x 3.5 with 125 sanstone = 18 kn/m Reaction line ld = 1.5 x ( ) = 30kN/m Supports Load on foundation = ( self wt)/150/1.5 = 0.17m proposed 500mm ok Therefore adequate allowing for load spread assuming 150kN/m2 allowable bearing pressure. Isolated wall say at door or window reveal therefore worst case situation 1000mm long and 250mm wide designed as column with pressure only on internal skin Load on masonry pier = 30 x 10 3/ (100 x 1000) = 0.33N/mm2 Assuming column 1000mm long x 250mm deep conservative Assume beta = 0.64 for two skins of masonry cavity with 125mm sand stone Allowable = 0.64 x 1000 x 100 x 5.0 / 3.5/ (1000 x 100)= 0.91N/mm2 ok Conservative as does not include bond with adjoining walls and load spread into the cross walls PROVIDE 300 CAVITY WALL WITH 100MM THICK INNER SKIN OF BLOCKWORK 100mm CAVITY AND 100MM EXTERNAL SKIN OF SANDSTONE FORMED WITH 50MM SURECAV CAVITY SPACER SYSTEM 50MM CELOTEX INSULATION TIED TOGETHER WITH 2.3MM GAUGE STAIFIX RT2 TYPE 2 ANCON WALL TIES OR SIMILAR AT 750MM HORIZONTAL AND 450 VERTICAL STAGGERED SureCav Ltd Cavity Spacer System Wall Tie Assessment May

8 6.0: WALL LATERAL LOAD DESIGN 6.1: Wall Type 1 adjacent to the eaves at first floor level with minimum dead loads above 2.5m high and say 6m wide Wind load = 1.15 kn/m2 Panel size = 6.0 x 2.5 = 15m t2ef = (0.66 x 200)2 = x 103 Allowable = 1500 x t2ef 2 or more sides continuous = 26.1 Try 100mm inner skin designed as propped cantilever 1m wide with external skin of 125mm sandstone construction in grade 3 mortar Tef = 0.66 x 200 =132 Allowable = 45 tef = 7128mm ok Moment = 1.2 x 1.15 x /8 = 1.07kN.m fkx = 0.25 N/mm2 grade 3 mortar in 125mm thick sandstone inner skin and 100mm thick blockwork inner skin z = 1000 x / 6 = 2.95 x 10 6 Moment of res = 0.25 x 2.95 x 10 6 / 3.5 = 210 x10 3N.mm2 ok PROVIDE 100mm THICK INNER SKIN OF MASONRY and 125mm THICK EXTERNAL SKIN OF SANDSTONE MASONRY DESIGNED AS PROPPED CANTILEVER WITH ADEQUATE ROOF BRACING IN TRUSSED TIMBER ROOFS IN GRADE 3 MORTAR THROUGHOUT SureCav Ltd Cavity Spacer System Wall Tie Assessment May

9 7.0 WALL TIE ASSESSMENT The following is now assessment of the wall ties in both grade 4 mortar and grade 3 mortar and using Ancon checking for both Staifix RT2 Type 2 an Staifix HRT4 Type 4 ties 225mm long and assuming all locations are exposed and above 150m altitude and wind or lateral pressure from all directions. A B C D E F F/D Wall tie Capacity Partial No of Wall Panel Wind Partial Utilization and mortar kn Safety Wall ties Lateral Cap pressure Safety % grade Factor m2 kn/m2 kn/m2 1.4 A/B x C E X 1.4 Type 4 13 Gauge Grade 4 Tension % Comp % Type 4 13 Gauge Grade 3 Tension % Comp % Type 2 10 Gauge Tension % Comp % THEREFORE PROVIDE ANCON TYPE 2 10 GAUGE WALL TIES OR 2.5 TIES PER M2 AND EVERY 225 AT DOOR AND WINDOW OPENINGS OR DOUBLE TIES EVERY 450MM CENTERS. NOTE ALSO THIS APPLIES AT ALL HEIGHTS ABOVE 150M OF ELEVATION THROUGH THE UNITED KINGDOM AS CONSERVATIVE LATERAL LOADING OF 1.15Kn/M2 FOR PROPORTIONAL ASSESSMENT SHOULD CONCERNS BE RAISED IN RESPECT OF BOND INTO MORTAR COULD USE 250MM LONG TIES NOTE ALSO ANCON TYPE 4 CAN BE USED IN WALLS NOTE EXPOSED IE INTERNAL OR PARTY WALLS SureCav Ltd Cavity Spacer System Wall Tie Assessment May

10