Ultimate Bearing Capacity of Bottom Sealing Concrete in Underwater Deep Foundation Pit: Theoretical Calculation and Numerical Analysis
Abstract
:1. Introduction
2. Theoretical Calculation
2.1. Ultimate Bending Moment and Ultimate Stress
2.1.1. Approximate Solution Derived by Elasticity Method
2.1.2. Traditional Method
2.2. Ultimate Bonding Strength
3. Numerical Simulation and Theoretical Verification Calculation
3.1. Numerical Simulation Based on ANSYS
3.2. Theoretical Verification Calculation
3.2.1. Maximum Tensile Stress Verification Calculation
3.2.2. Bonding Strength Verification Calculation
4. Discussion
- It can be seen that the tensile stress of the bottom sealing concrete calculated by the approximate solution is closer to the monitored value than the traditional method. Therefore, the approximate solution is more accurate than the traditional method.
- The result calculated by traditional method is safer in engineering. But, if the traditional method is adopted, the amount of concrete required during construction will be much larger, which will cause waste of materials.
- The numerical simulation method is closer to the monitored value than the above two theoretical calculation methods, but the steps are relatively cumbersome and require more time.
- When the accuracy required in the project is not high, the traditional method can be used; when the required accuracy is moderate, the approximate solution can be used; when the required accuracy is high, the numerical simulation method can be used.
- In the future research, for the elastic mechanics method, the influence of the holes in the bottom-sealed concrete can be considered to improve the accuracy of the calculation; for the numerical simulation method, the operation steps can be simplified.
5. Conclusions
- When calculating the maximum compressive stress and tensile stress of the bottom sealing concrete, the concrete can be regarded as an isotropic, continuous, uniform, and small deformation elastic material, and the bottom sealing concrete can be simplified into an elastic thin slab, and the elasticity method is used for the calculation. The traditional method can also be used to divide the bottom sealing concrete slab along the long side and divide it into several concrete beams. The maximum stress obtained by the approximate solution is closer to the actual monitoring value than the traditional method.
- Equation (18) can be used to calculate the ultimate bonding force between the bottom sealing concrete and the steel sleeves. The calculated bonding force is only an average value, and it will be slightly smaller, which can be used to make a rough estimate.
- For the calculation of the maximum compressive stress, tensile stress, and cohesive force of the bottom sealing concrete, it can be assumed that the bottom sealing concrete material is isotropic, homogeneous, and dense, and the ANSYS finite element software can be used for numerical simulation.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
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Parameters | Values |
---|---|
Piles’ Length | 49.0 m |
Piles’ Diameter | 2.0 m |
Piles’ Number | 24 |
Cofferdam’s Long | 27.5 m |
Cofferdam’s Wide | 19.2 m |
Thickness of the Bottom Sealing Concrete | 3.0 m |
Data Sources | Maximum Tensile Stress/MPa | Relative Error Compared with Monitoring Data |
---|---|---|
Approximate Solution | 0.95 | 2.96 |
Traditional Method | 5.70 | 22.75 |
Numerical Simulation | 0.39 | 0.625 |
Monitoring Data | 0.24 | 0 |
Data Sources | Bonding Force/kPa |
---|---|
Equation Calculation | 89.61 |
Numerical Simulation | 93.75 |
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Chen, S.; Li, Y.; Guo, P.; Zuo, X.; Liu, Y.; Yuan, H.; Wang, Y. Ultimate Bearing Capacity of Bottom Sealing Concrete in Underwater Deep Foundation Pit: Theoretical Calculation and Numerical Analysis. Machines 2022, 10, 830. https://doi.org/10.3390/machines10100830
Chen S, Li Y, Guo P, Zuo X, Liu Y, Yuan H, Wang Y. Ultimate Bearing Capacity of Bottom Sealing Concrete in Underwater Deep Foundation Pit: Theoretical Calculation and Numerical Analysis. Machines. 2022; 10(10):830. https://doi.org/10.3390/machines10100830
Chicago/Turabian StyleChen, Shuo, Yonghai Li, Panpan Guo, Xiaohan Zuo, Yan Liu, Haiping Yuan, and Yixian Wang. 2022. "Ultimate Bearing Capacity of Bottom Sealing Concrete in Underwater Deep Foundation Pit: Theoretical Calculation and Numerical Analysis" Machines 10, no. 10: 830. https://doi.org/10.3390/machines10100830