APPENDIX 5: CONSTRUCTION CHECKLISTS

Transcription

1 APPENDIX 5: CONSTRUCTION CHECKLISTS This appendix presents the construction checklists for the various retaining wall mitigation strategies: 10.1 Void Fill 10.2 Surface Bond Overlay 10.3 Reinforced Overlay 10.4 New Retaining Wall and Buttress 10.5 Gabion Erosion Protection

2 D10.1 Retaining Wall Void Repair Remove loose and flakey masonry using wire brush Remove loose stones and debris from cavity Wet cavity prior to mortar placement Mix Mortar Place mortar bed in cavity Place stone and mortar 1 Surface Preparation a All loose and flakey material has been removed Yes/No/NA Yes/No/NA b All loose stone and debris has been removed Yes/No/NA Yes/No/NA c Cavity sufficiently wetted prior to mortar placement Yes/No/NA Yes/No/NA 2 Mortar Mixing a Use mortar 1:3 mix Yes/No/NA Yes/No/NA b Use clean, fine river sand Yes/No/NA Yes/No/NA c Use clean water (not salty or muddy) Yes/No/NA Yes/No/NA d Use Type 1 Cement Yes/No/NA Yes/No/NA e Mix on a clean, concrete or asphalt surface, not on dirt Yes/No/NA Yes/No/NA f Turn over 3 times or until color is uniform Yes/No/NA Yes/No/NA g Do not use too much water! Add water slowly Yes/No/NA Yes/No/NA 3 Implementation If step not correctly implemented, following advice given: Advice followed? a Mortar bed placed in cavity to thickness of 2.0cm /NA Yes/No/NA b Select stones of similar size and shape to existing wall /NA Yes/No/NA c Wet stones prior to placement /NA Yes/No/NA d Prepare a reasonable amount of mortar to avoid adding water /NA Yes/No/NA e Stones and mortar properly placed /NA Yes/No/NA f Ensure a flush face and that stones do not project significantly from face of wall /NA Yes/No/NA Homeowner Signature: Overall Assessment: Meets Minimum Standard? BC Engineer Signature: Comments:

3 D10.2 Surface bond face of retaining wall with mortar Remove loose and flakey mortar and stone using wire brush Place wire mesh reinforcement Wet wall prior to applying cement plaster Mix Mortar Apply 5 cm thick layer of plaster to face of the wall 1 Surface Preparation a All loose and flakey material has been removed Yes/No/NA Yes/No/NA b Wall wetted prior to apllication of cement plaster Yes/No/NA Yes/No/NA 2 Wire Mesh Placement a Embed steel hooks in mortar of existing wall at 1.0 meter centers, horizontally and vertically. Yes/No/NA Yes/No/NA b Secure wire mesh on steel hooks with binding wire at each intersection. Yes/No/NA Yes/No/NA 3 Mortar Mixing a Use mortar 1:3 mix / NA Yes/No/NA b Use clean, fine river sand / NA Yes/No/NA c Use clean water (not salty or muddy) / NA Yes/No/NA d Use Type 1 Cement / NA Yes/No/NA e Mix on a clean, concrete or asphalt surface, not on dirt / NA Yes/No/NA f Turn over 3 times or until color is uniform / NA Yes/No/NA g Do not use too much water! Add water slowly / NA Yes/No/NA 4 Implementation a Wall coated with 5.0 cm of plaster applied in minimum of two layers. / NA Yes/No/NA Homeowner Signature: Overall Assessment: Meets Minimum Standard? BC Engineer Signature: Comments:

4 D10.3 Reinforced Overlay At both ends of the overlay break out small holes in the slab obove(diameter 10cm) Using these holes as a guide, set up stringline on top of slab to indicate the line of the overlay below Break-out 10cm diameter 30cm spacing in wall blocks. Remove debris from holes Insert #2 bars through 30cm centers Shutter top of overlay Excavate anchor trench to required dimensions Place formwork and reinforcement for floor slab and anchor trench (inside structure) Mix and pour concrete Ensure adequate curing of concrete Remove formwork only after 48 hours 1 Preparatory works a Working area is clear and secured Yes/No/NA Yes/No/NA b Ribs either side of wall are propped with metallic 1m centers Yes/No/NA Yes/No/NA 2 Breaking-out of wall a Line of overlay correctly set-out using a stringline Yes/No/NA Yes/No/NA b 10cm diameter 30cm centers formed in bottom of wall Yes/No/NA Yes/No/NA 3 Reinforcement a Type of reniforcement RIBBED Yes/No/NA Yes/No/NA b Minimum Strength = Grade 60 Yes/No/NA Yes/No/NA 5 FORMWORK and CONCRETE SPACER a Formwork is good quality (not warped) Yes/No/NA Yes/No/NA b Space between steel and formwork minimum 2.5 cm Yes/No/NA Yes/No/NA c Use concrete spacers as req to maintain cover Yes/No/NA Yes/No/NA d Maximum size for concrete spacer is 3 cm x 3 cm x 3 cm Yes/No/NA Yes/No/NA e Use binding wire in concrete spacer Yes/No/NA Yes/No/NA 6 CONCRETE MIXING a Use Mix 1:2:4 Yes/No/NA Yes/No/NA b Use crushed, angular gravel Yes/No/NA Yes/No/NA c Use gravel with size less than 2 cm Yes/No/NA Yes/No/NA d Use clean, washed river sand Yes/No/NA Yes/No/NA e Use clean water (not salty or muddy) Yes/No/NA Yes/No/NA f Use Type 1 Cement Yes/No/NA Yes/No/NA g Mix on a clean, concrete or asphalt surface, not on dirt Yes/No/NA Yes/No/NA h Use a mechanical mixer, if possible Yes/No/NA Yes/No/NA i Batch out gravel, then sand, then cement Yes/No/NA Yes/No/NA j Turn over 3 times or until color is uniform Yes/No/NA Yes/No/NA k Do not use too much water! Add water slowly Yes/No/NA Yes/No/NA l Use slump test or hand test for water content Yes/No/NA Yes/No/NA 7 CONCRETE POURING and CURING a Wet formwork and steel before pouring concrete Yes/No/NA Yes/No/NA b Use concrete within 90 minutes of mixing with water if from factory Yes/No/NA Yes/No/NA c if manually use in less than 30 minutes Yes/No/NA Yes/No/NA d Use rod to consolidate concrete around reinforcement Yes/No/NA Yes/No/NA e Complete entire pour within one day Yes/No/NA Yes/No/NA f If concrete pouring must stop, use a diagonal joint with stones Yes/No/NA Yes/No/NA g Have plastic on standby, cover if it rains Yes/No/NA Yes/No/NA h Cure for minimum 3 days by sprinkling clean water, Yes/No/NA Yes/No/NA i Cure 5 times perday : MORNING, At 8, 10 Yes/No/NA Yes/No/NA j AFTERNOON: 12, 14, 16, pour water slowly Yes/No/NA Yes/No/NA 8 CONCRETE INSPECTION a Remove formwork after 14 full days Yes/No/NA Yes/No/NA b If steel showing, demolish and rebuild Yes/No/NA Yes/No/NA d Any cracks larger than 3 mm Yes/No/NA Yes/No/NA e Many cracks in one location Yes/No/NA Yes/No/NA f Diagonal or vertical cracks anywhere in the beam Yes/No/NA Yes/No/NA g If any of the above exist, demolish concrete and repour Yes/No/NA Yes/No/NA Homeowner Signature: Overall Assessment: Meets Minimum Standard? BC Engineer Signature: Comments:

5 D10.4 Construct New Retaining Wall Determine lines and offset for retaining wall Prepare wall foundation Mix mortar Set stones Construct drainage elements Backfill wall 1 Preparatory works a Working area is clear and secured Yes/No/NA Yes/No/NA b Lay out retaining wall, consider batter of retaining wall face Yes/No/NA Yes/No/NA 2 Wall Foundation a Excavate trench to required depth, depending on soil type/embedment requirements Yes/No/NA Yes/No/NA b Place 10cm thick blinding concrete layer, if soil conditions require Yes/No/NA Yes/No/NA 3 Mortar Mixing a Use mortar 1:3 mix Yes/No/NA Yes/No/NA b Use clean, fine river sand Yes/No/NA Yes/No/NA c Use clean water (not salty or muddy) Yes/No/NA Yes/No/NA d Use Type 1 Cement Yes/No/NA Yes/No/NA e Mix on a clean, concrete or asphalt surface, not on dirt Yes/No/NA Yes/No/NA f Turn over 3 times or until color is uniform Yes/No/NA Yes/No/NA g Do not use too much water! Add water slowly Yes/No/NA Yes/No/NA 4 Stone Placement a Use stone that is sound, durable, angular, and free from significant cracks or flaws Yes/No/NA Yes/No/NA b Use stone with a minimum size of 20cm Yes/No/NA Yes/No/NA c Prior to placement ensure that stones are clean, then saturate with water. Yes/No/NA Yes/No/NA d Place mortar bed with minimum thickness of 2cm Yes/No/NA Yes/No/NA e Well bed all stones in freshly placed mortar Yes/No/NA Yes/No/NA f Place stones to line in courses roughly leveled up. Periodically check face batter. Yes/No/NA Yes/No/NA g Maximum joint thickness of 2.5cm Yes/No/NA Yes/No/NA h Stagger vertical joints Yes/No/NA Yes/No/NA 5 Construct Drainage Elements a Place 10cm diameter PVC drainage pipe at 1.5m centers horizontally Yes/No/NA Yes/No/NA b Protect PVC pipe from damage during stone placement Yes/No/NA Yes/No/NA 6 Backfill wall a Place drainage layer of compacted gravel and native backfill concurrently as wall construction proceeds. Yes/No/NA Yes/No/NA b Place and compact backfill in 30cm increments using handheld tamper Yes/No/NA Yes/No/NA Homeowner Signature: Overall Assessment: Meets Minimum Standard? BC Engineer Signature: Comments:

6 D10.5 Construct New Gabion Wall Determine lines and offset for gabion wall Prepare wall foundation Assemble gabion baskets Fill Gabion Cells Backfill wall 1 Preparatory works a Working area is clear and secured Yes/No/NA Yes/No/NA b Lay out retaining wall, consider batter of retaining wall face Yes/No/NA Yes/No/NA 2 Wall Foundation a Excavate trench to required depth, depending on soil type/embedment requirements Yes/No/NA Yes/No/NA 3 Assemble Gabion Baskets a Do not damage baskets during transport or construction. Yes/No/NA Yes/No/NA b Rotate basket panels and diaphrams into position and join vertical edges with lacing wire per detail. Yes/No/NA Yes/No/NA c Interconnect adjacent baskets on top and vertical edges using lacing wire per detail. Yes/No/NA Yes/No/NA d Remove all kinks and folds in the wire mesh and properly align baskets. Yes/No/NA Yes/No/NA 4 Fill Gabion Cells a Use stone that is sound, durable, angular, and free from significant cracks or flaws Yes/No/NA Yes/No/NA b Use stones with cubic dimension between 100mm and 200mm. Yes/No/NA Yes/No/NA c Place rock carefully in basket to prevent bulging of the baskets and to minimize voids in stone fill. Yes/No/NA Yes/No/NA d Maintain basket alignment during cell filling. Yes/No/NA Yes/No/NA e Fill cells so that no cell is filled more than 0.3m above an adjacent cell. Repeat until basket is full and lid bears on final rock layer. Yes/No/NA Yes/No/NA f Secure the lid to sides,ends, and diaphrams with lacing wire per detail. Yes/No/NA Yes/No/NA g if required, place empty gabion basket on top of completed basket and repeat cell filling process until structure is complete. Yes/No/NA Yes/No/NA h If possible, stagger vertical joints between baskets by at least one cell length. Yes/No/NA Yes/No/NA 5 Backfill wall a Concurrently with the cell filling operation, backfill the area behind the gabion structure with native material. Yes/No/NA Yes/No/NA b Place and compact backfill in 30cm increments using handheld tamper Yes/No/NA Yes/No/NA Homeowner Signature: Overall Assessment: Meets Minimum Standard? BC Engineer Signature: Comments: