Tham khảo tài liệu 'các thành phần của công trình', kỹ thuật - công nghệ, kiến trúc - xây dựng phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Banked excavation with terrace for the collection of precipitating material terrace surface level not lower m than upper surface of cellar floor lower edge of foundatioruX1 existing building section ground level floor level Al ground water existing building envisaged building - ground level limit of soil excavation 3 1 1 j lower edge of 1 1 foundation limit of soil excavation following completion of underpin 11 7 ground water excavation cellar floor level underpin masonry concrete or reinforced concrete Securing existing neighbouring buildings Section through foundations - 7 Section through underpinning - 5 jT Plan view 4 first building section THE BUILDING SITE Foundations Excavation Trenches Surveying site investigation appraisal Failure to accurately assess the building site and water table conditions and to specify the correct foundations generally leads to irreparable structural damage and serious cost overruns. Lateral ground displacement due to the load on the foundations causes the foundations to sink into the ground or become laterally displaced. This leads to total failure of the foundations. Settlement due to compression of the building site under the foundations due to the load on the foundations and or loads caused by neighbouring structures leads to deformations and damage cracks in the superstructure. Where there is adequate local knowledge of the nature mechanical properties stratification and bearing strength of the sub-soil layers calculations can be made which determine the dimensions of shallow foundations individual and strip foundations foundation pads and rafts and deep foundations pile foundations . If such knowledge is not available timely investigation of the ground is required if possible in consultation with an appropriate expert. This involves examination of the strata by excavation manual or mechanical excavator borings auger rotary bit or core drilling with the extraction of samples and probes. The number and depth of inspections .
