Hello. Maybe someone here has already dealt with a similar problem.
For our single-family house on a slope, we followed the foundation recommendations according to the geotechnical report.
There is 40cm (16 inches) of recycled gravel laid in two layers and compacted on rocky ground. The structural engineer requested a plate bearing test at two points, which failed on the first try. The recommendation was to moisten and compact further. That was done. The second test also narrowly failed.
We moistened and compacted again. Unfortunately, the third test failed as well.
Here are the values from the plate bearing tests:
First attempt:
EV1: 99.2 MN/m²
EV2: 36.1 MN/m²
EV2/EV1 = 2.75
Second attempt:
EV1: 45.1 MN/m²
EV2: 118.4 MN/m²
EV2/EV1 = 2.61
Third attempt:
EV1: 45.3 MN/m²
EV2: 118.4 MN/m²
EV2/EV1 = 2.61
The value EV2/EV1 must be less than or equal to 2.5 to meet the requirements.
The compactor used is a 500kg (1,100 lbs) Wacker DPU. Is this generally sufficient, or do we need to bring in heavier equipment?
What was your experience, and what can we do?
For our single-family house on a slope, we followed the foundation recommendations according to the geotechnical report.
There is 40cm (16 inches) of recycled gravel laid in two layers and compacted on rocky ground. The structural engineer requested a plate bearing test at two points, which failed on the first try. The recommendation was to moisten and compact further. That was done. The second test also narrowly failed.
We moistened and compacted again. Unfortunately, the third test failed as well.
Here are the values from the plate bearing tests:
First attempt:
EV1: 99.2 MN/m²
EV2: 36.1 MN/m²
EV2/EV1 = 2.75
Second attempt:
EV1: 45.1 MN/m²
EV2: 118.4 MN/m²
EV2/EV1 = 2.61
Third attempt:
EV1: 45.3 MN/m²
EV2: 118.4 MN/m²
EV2/EV1 = 2.61
The value EV2/EV1 must be less than or equal to 2.5 to meet the requirements.
The compactor used is a 500kg (1,100 lbs) Wacker DPU. Is this generally sufficient, or do we need to bring in heavier equipment?
What was your experience, and what can we do?
P
Pitiglianio24 Aug 2022 20:31For your information:
After several leveling layers (LPs) failed, as described in the original post, we removed all the gravel, re-compacted the base layer, and reinstalled the recycled concrete (RC) gravel in two layers, thoroughly watering it during installation.
We let the entire mess rest for two weeks and then commissioned new leveling layers. And behold...
... it finally worked out.... 🙂
After several leveling layers (LPs) failed, as described in the original post, we removed all the gravel, re-compacted the base layer, and reinstalled the recycled concrete (RC) gravel in two layers, thoroughly watering it during installation.
We let the entire mess rest for two weeks and then commissioned new leveling layers. And behold...
... it finally worked out.... 🙂
S
Shino718915 May 2023 12:47Pitiglianio schrieb:
For your information:
After several levelings (LPs) failed, as described in the original post, we removed all the gravel again, re-compacted the base layer, and reinstalled the recycled concrete gravel in two layers while thoroughly wetting it.
Let the whole mess settle for two weeks and then ordered new levelings. And look...
... it finally worked out.... 🙂 Hey, we unfortunately have the same problem. We had heavy rain, maybe even too heavy at times, and you can still feel that the soil on the surface is a bit soft even after waiting three days. Could you maybe tell me how you handled the costs? Who took on all the extra work?
P
Pitiglianio15 May 2023 13:06@Shino7189
Although the load plate bearing tests were specified by the general contractor, they were still carried out as part of our own scope of work.
I had negotiated a flat rate with my deep foundation contractor for the proper preparation of the subgrade. He stuck to this price despite additional effort. We then shared the costs for the extra load plate tests.
Although the load plate bearing tests were specified by the general contractor, they were still carried out as part of our own scope of work.
I had negotiated a flat rate with my deep foundation contractor for the proper preparation of the subgrade. He stuck to this price despite additional effort. We then shared the costs for the extra load plate tests.