Browse Forums Landscape & Garden Design 1 Jan 27, 2011 9:43 pm Hi all, I have a retaining wall in my backyard which is about 1.4m high and its been there since house was built. The wall is still in good condition, no cracks or movements. It made out of bricks. After that retaining wall there is about 1.5m to the colourbond fence. So i have this 1.5 deep and 8 meters long empty hole in my backyard. There is no sewer or any other underground services going through there. I dont know why it was done this way but anyhow i started building a new retaining wall in front of the existing. New retaning wall has concrete footings 400mm deep by 400mm wide with 12mm reo bars in it and starter bars going up every 400mm. Starter bars are 16mm. Besser blocks used are 190 by 190 by 390. The wall is 1.6m high with horizontal reo bars going trought it every second row of the blocks. The blocks will be filled with concrete. MY QUESTION IS?? which i should have asked before this was done. Is this new retaining wall good enough to keep the pressure of dirty behind it, remember there is only 1.2m to the existing retaining wall that is behind the new one. i also have 50mm pipes at the bottom for drainage and blue metal. Re: Retaining wall?? 3Jan 28, 2011 8:04 am 400mm deep is about 20% of what is should be. A good rule for retaining walls is go at least as deep in the ground as you want to be above. If the ground slopes down to the wall then it will need to be deeper again. Also some types of bricks are not suitable over 1.0 high out of ground. 50mm not big enough either IMO(should be at least 90mm) In Victoria you must have an engineer design above 600mm above ground. Sounds like you should get an inspector in to look at it and you will probably be pulling it down and starting again. Re: Retaining wall?? 4Jan 28, 2011 8:31 am but its only holding the dirt that is between the new and old retaining wall (1.2m) and there is no slope. from wall to wall is 1.2m its 1.6m deep and 8 m wide and closed off at the ends. I didn't think there would be a lot of pressure there?? Re: Retaining wall?? 5Jan 28, 2011 11:27 am I agree, it seems you are retaining very little. The reason retaining walls shift is not only the wieght being retained but the process of clay shrinking and cracking, then fine clay particles filling those gaps so when the clay swells with water agian the volume has increased and the wall is pushed. If you are retaining such a small volume, have good drainage and use a sandy soil (NOT clay) to backfill I think you will be okay. Just hope you don't need to get it inspected by council. Building an Eden Brae Saville 27 http://karry327.blogspot.com/ Building thread https://forum.homeone.com.au/viewtopic.php?f=31&t=44247 Re: Retaining wall?? 6Jan 28, 2011 2:32 pm ^^^ If the council looked at it they would say pull it down. Can you get a picture of the area? A wide shot will help as well. Its hard to tell how far off the house you are talking about. Re: Retaining wall?? 7Jan 28, 2011 4:24 pm Council?? i didnt think they have to get involved, its on my property. I will take some photos and show you. Basically it looks like a box now, new retaining wall is 8m long and at the ends it turns 90dergrees back towards the old retaining wall. distances between the walls is 1.2m Ohh now i am stressing a bit. Re: Retaining wall?? 8Jan 28, 2011 5:05 pm Council permission is required in most areas for walls over 1m high. They will find out only if, 1 Nieghbours complain 2 You need an occupation cerytificate and the inspector comes visiting 3 The wall collapses 4 You sell and someone picks it up on the property search 5 You tell them Hopefully you can avoid these situations Building an Eden Brae Saville 27 http://karry327.blogspot.com/ Building thread https://forum.homeone.com.au/viewtopic.php?f=31&t=44247 Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5179 Thanks for the insights, that makes perfect sense, and yeah, I will be leaning on the experience of the excavator operator entirely. 6 16132 Hi All, I engaged a tradie to install concrete retaining wall 600-800mm high over 32 meters in Victoria. Sleepers are 200*75*2000 mm installed over 17 steel posts. I… 0 6900 |