SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES
Introduction: Saint Petersburg is characterized by complex engineering and geological conditions due to the presence of a significant mass (with a thickness of 20…30 m or more) of highly deformable soils with deformation moduli of 5…10 MPa. Besides, due to long-term geological processes that took pl...
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| Format: | Article |
| Language: | English |
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Saint Petersburg State University of Architecture and Civil Engineering
2020-03-01
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| Series: | Architecture and Engineering |
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| Online Access: | https://aej.spbgasu.ru/index.php/AE/article/view/276/156 |
| _version_ | 1818096905728557056 |
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| author | Vladimir Konyushkov Van Trong Le |
| author_facet | Vladimir Konyushkov Van Trong Le |
| author_sort | Vladimir Konyushkov |
| collection | DOAJ |
| description | Introduction: Saint Petersburg is characterized by complex engineering and geological conditions due to the presence of a significant mass (with a thickness of 20…30 m or more) of highly deformable soils with deformation moduli of 5…10 MPa. Besides, due to long-term geological processes that took place in the territory of Saint Petersburg thousands of years ago, these soils are extremely unevenly distributed in depth and area of occurrence. However, according to modern requirements for city development, deeper underground structures and higher buildings are needed. In terms of geotechnical solutions, it is possible to meet these requirements by using deep piles. Purpose of the study: The authors of the paper made an approximate brief classification of the geological conditions of Saint
Petersburg based on the genesis, depth of occurrence, and physical and mechanical properties, and developed a method for more accurate calculations of the bearing capacity of deep bored piles. Methods: In the course of the study, the authors performed statistical processing of 600 values of the bearing capacity of bored piles, calculated according to the requirements of standards and determined by the results of field tests. In addition, they performed a non-linear extrapolation of side friction and resistance values (for soils with a depth of up to 100 m). Results: The paper presents the assessment of the bearing capacity of bored piles depending on their depth in glacial moraine and pre-quaternary vendian deposits. Using the nonlinear extrapolation, the authors calculated the side friction and resistance under the toe of bored piles for further design of pile foundations with deep bored piles (at a depth of up to 100 m). Discussion: According to statistical studies, the actual bearing capacity of bored piles is significantly higher than the design one calculated according to the requirements of corresponding standards (by 1.6...2.6 times). This is due to the fact that soils with significantly differing strength and deformation characteristics are located along the side and under the toe of bored piles. The stronger the soil where the most part of the pile is located, the more the bearing capacity error is (towards underestimation). The paper presents studies confirming this statement. |
| first_indexed | 2024-12-10T23:12:03Z |
| format | Article |
| id | doaj.art-f19f5573b9504fe39b85738d89130dee |
| institution | Directory Open Access Journal |
| issn | 2500-0055 2500-0055 |
| language | English |
| last_indexed | 2024-12-10T23:12:03Z |
| publishDate | 2020-03-01 |
| publisher | Saint Petersburg State University of Architecture and Civil Engineering |
| record_format | Article |
| series | Architecture and Engineering |
| spelling | doaj.art-f19f5573b9504fe39b85738d89130dee2022-12-22T01:29:55ZengSaint Petersburg State University of Architecture and Civil EngineeringArchitecture and Engineering2500-00552500-00552020-03-0151364410.23968/2500-0055-2020-5-1-36-44SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILESVladimir Konyushkov0Van Trong Le1Saint Petersburg State University of Architecture and Civil EngineeringSaint Petersburg State University of Architecture and Civil EngineeringIntroduction: Saint Petersburg is characterized by complex engineering and geological conditions due to the presence of a significant mass (with a thickness of 20…30 m or more) of highly deformable soils with deformation moduli of 5…10 MPa. Besides, due to long-term geological processes that took place in the territory of Saint Petersburg thousands of years ago, these soils are extremely unevenly distributed in depth and area of occurrence. However, according to modern requirements for city development, deeper underground structures and higher buildings are needed. In terms of geotechnical solutions, it is possible to meet these requirements by using deep piles. Purpose of the study: The authors of the paper made an approximate brief classification of the geological conditions of Saint Petersburg based on the genesis, depth of occurrence, and physical and mechanical properties, and developed a method for more accurate calculations of the bearing capacity of deep bored piles. Methods: In the course of the study, the authors performed statistical processing of 600 values of the bearing capacity of bored piles, calculated according to the requirements of standards and determined by the results of field tests. In addition, they performed a non-linear extrapolation of side friction and resistance values (for soils with a depth of up to 100 m). Results: The paper presents the assessment of the bearing capacity of bored piles depending on their depth in glacial moraine and pre-quaternary vendian deposits. Using the nonlinear extrapolation, the authors calculated the side friction and resistance under the toe of bored piles for further design of pile foundations with deep bored piles (at a depth of up to 100 m). Discussion: According to statistical studies, the actual bearing capacity of bored piles is significantly higher than the design one calculated according to the requirements of corresponding standards (by 1.6...2.6 times). This is due to the fact that soils with significantly differing strength and deformation characteristics are located along the side and under the toe of bored piles. The stronger the soil where the most part of the pile is located, the more the bearing capacity error is (towards underestimation). The paper presents studies confirming this statement.https://aej.spbgasu.ru/index.php/AE/article/view/276/156glacial moraine and pre-quaternary vendian depositsside frictionresistance under the pile toebearing capacity of bored piles at a depth of up to 100 m. |
| spellingShingle | Vladimir Konyushkov Van Trong Le SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES Architecture and Engineering glacial moraine and pre-quaternary vendian deposits side friction resistance under the pile toe bearing capacity of bored piles at a depth of up to 100 m. |
| title | SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES |
| title_full | SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES |
| title_fullStr | SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES |
| title_full_unstemmed | SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES |
| title_short | SIDE FRICTION OF SANDY AND CLAY SOILS AND THEIR RESISTANCE UNDER THE TOE OF DEEP BORED PILES |
| title_sort | side friction of sandy and clay soils and their resistance under the toe of deep bored piles |
| topic | glacial moraine and pre-quaternary vendian deposits side friction resistance under the pile toe bearing capacity of bored piles at a depth of up to 100 m. |
| url | https://aej.spbgasu.ru/index.php/AE/article/view/276/156 |
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