Plots with filling is a major problem in many housing projects including reputable ones. But once a plot has been filled and left exposed to the elements, I believe the soil does start getting compacted slowly, and if a roller is used, the process I am sure can be accelerated reducing the risks to the future building. Can any respected member with construction experience kindly share as to how much time may be required to get decent soil compaction on a filled plot to make it suitable for construction? Or is building rafts the better option? Thanks.
Compaction in a natural process takes millions of years to complete. . These are ancient formations of soil and stones formed in slow and complex system…in my opinion plots with fillings are worth less. …
Million $$$ is right in saying that compaction is time taking process. Roller cannot compact unless someone can find a roller having weight equal to the building's dead load.
But filling plots are not worthless. Some people build rafts. But better to make column's base till original and natural level of soil. Raise the columns till plinth level and join it through beam. It's Murree style of construction to make us understand.
But for all this, you must hire structure engineer. We are not fit on whom you should depend.
You can also make basement on such plots if you have budget.
I am a structural engineer and have exp in dealing with such things.
Remember not to build foundation of any type on filli material, unless you compact and improve load bearing capacity by using soil improvement techniques. Such techniques are expensive and soil compaction can also cost you more.
Second go to nsl or natural surface level and put your individual column footing there. There is no comparison of bearing capacity of nsl.
Raft can also settle along with fill so don't rely on fill.
Usman is absolutely right.
@Kashif Sheikh. One of my friend had filling plot as it was cheaper. He built basement and ground floor only till he ran out of budget. Than he built 1st floor after few years.
I myself ran out of budget and hadn't finished the basement though contructed structure was full. I am finishing it after an year.
Filling plots are not crap. It has good worth but a bit less than level plots. Builders and investors avoid such plots as they get less return. For home builders it's not as bad as people think.