Browse Forums General Discussion 1 Feb 28, 2012 3:42 pm I have just been emailed a copy of our soil test results and it say; The soil profiles encountered are shown on the attached log section. No water table was encountered during our testing programme. From the sample tested in the laboratory, the indicative values for the plastic soils on site are, a liquid limit value of 47, a linear shrinkage value of 14.0 % and a shrink-swell of 2.8 %. We have calculated the Ys of the soil profile encountered at test site No. 1 and found it to be in the range of 30mm - 35mm. This Ys was calculated by using the Ground Movement Calculation Method. This method is covered under Clause 2.3 of AS2870 and the calculation considers the liquid limit, linear shrinkage and or shrink-swell of the sample(s) tested in our laboratory as well as the influence of the zone of cracking. The calculation also has correction factors for a reduction in the soil suction effect with increasing depth and we have assumed a soil suction range as recommended in AS2870-2011 Clause 2.3.3. The specific calculated Allowable Bearing Pressures are shown on the log section. Our field testing has shown that an allowable bearing pressure of only 35 kPa is available in the natural undisturbed soil profile at depth 400 mm to 500 mm below our test surface level. Therefore by definition according to Section 2 of AS2870 this site must be classified as Class ‘P’ because the allowable bearing capacity is less than 50 kPa. It does go onto say some other things but this is the main part I don't understand. Can someone please help give me a general idea of what this means because I hate not knowing & can't get onto my husband to explain as he's in meetings all afternoon!! Thanks Bec Re: Soil test results, What does this mean?? 2Feb 28, 2012 3:47 pm For info on our build: viewtopic.php?f=31&t=43093 Built the McLaren by Dechellis - slab down 22 Feb - handover 30 Aug 2011 - and gardens finished 9 Dec 2012!! Re: Soil test results, What does this mean?? 3Feb 28, 2012 4:29 pm brbp No water table was encountered during our testing..... Therefore by definition according to Section 2 of AS2870 this site must be classified as Class ‘P’ because the allowable bearing capacity is less than 50 kPa. The above is all you really need to know. In other word no groundwater, and Class 'P' foundations which will probably mean additional site costs The rest is just technical jargon to inform any civil engineer how they arrived at the classification. You would need a fair bit of study to understand the jargon The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Soil test results, What does this mean?? 4Feb 28, 2012 5:57 pm P site = problem site and foundations and slab will be engineered accordingly. Thats why engineers get the big money as they say, end of the day there the ones who have to make sure they get it right. I guess the biggest main thing you need to know is it will cost you more money. depending on what allowance your builder has put in, that will determain how much more it will cost you. Cheers mgilla Re: Soil test results, What does this mean?? 5Mar 26, 2012 5:20 am Site drainage during construction is the most critical part of building yet it is often neglected. Have look at your soil report and see what recommendations are there. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Soil test results, What does this mean?? 6Mar 26, 2012 9:42 am I'd simply call the Geotech Engineering group that did the testing and compiled the soil test and ask them to break it down in simple terms for you. All engineers speak in a language of their own! Re: Soil test results, What does this mean?? 7Mar 26, 2012 10:45 am To summarise: "The land on your block is squishy. We're gonna need a bigger boat. Uh, slab". But yeah, basically the soil both absorbs more water than you'd like, and it can't handle a lot of weight without compressing. It's also inconsistent, so weight won't be equally distributed the way it needs to be, which would mean the slab will crack and sink. Building a Delta 21 at Craigieburn - http://homeofzero.blogspot.com.au/ Deposit: 26/02. Contract: 22/05. Settlement: 29/05. Site start: 18/10. Three options 1 Ask the liquidator 2 Find another PD customer and ask the source of their report 3 Pay for new report 3 12573 We were lucky in that our old house was so small (86 square metres) compared to the new house, they were able to take enough readings around the old backyard house before… 8 37298 Hi Building Expert, Thank you for the feedback, much appreciated, there is also a code of conduct for building surveyors which they need to follow as well. I am looking… 4 3683 |