الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
As a summary for the studies made in the previous chapters, two case studies Sukhumvit Subway Station, Bangkok, and State Street Subway, Chicago were reanalysed using the hardening soil small strain model. Then, comparisons between the results of the analysis and the site measurements were applied. The hardening soil stiffness parameter (E50ref ) was calculated using Finno and Calvello (2005).
Parametric studies for the Bangkok case study were conducted to clarify the effect of the concrete thermal shrinkage due to hydration processes of the supported slabs, the wall thickness, and the wall-length on the wall deformations. Also, comparisons between different constitutive models were adopted to conclude the difference between each constitutive model on the wall deformations such as Mohr-Coulomb model, Modified Mohr-Coulomb model, Hardening soil model, Hardening soil small strain model, and soft soil model.
A study of the Port-said soil from Egypt was processed to investigate the effect of the deep excavation in the soft clay soil, which is extended to depths from the ground surface. Also, the effect of numerical analysis on the two cases like Sukhumvit Subway Station, Bangkok, and Chicago-State Subway, Chicago. Then the analysis results were compared with values estimated from the semi-empirical/empirical methods.
7.2 Conclusion
(1) Through the analysis of the two cases studies using the approach proposed by Finno and Calvello (2005) to determine the loading stiffness parameter (E50), the results of the wall deformations compatible with the measured deformations from the site. In the top-down construction case (Bangkok case), the analysed maximum lateral deformation is increased by percentage 21% from the measured one. In the down-down construction case (Chicago case), the analysed maximum lateral deformation is increased by percentage 6% from the measured one.
(2) In the case of Bangkok, concrete shrinkage effect on slabs shall be considered in the analysis of the system as it has a noticeable impact on the deformations. The temperature change is regarded as -35°, referring to Dong et al. (2014).
(3) It is recommended to refer to the Egyptian code ECP 2018 to calculate the concrete shrinkage on slabs for projects in Egypt similar to Bangkok case.
(4) In the case of construction by the top-down method, although the depth of excavation up to 21m, the diaphragm wall moved 35 mm (field measurements), conversely in the case of construction by the down-top method and the depth of excavation 12m, the secant pile wall moves 55 mm (field measurements). Based on the results of wall movements for the two construction techniques, the top-down method showed fewer deformations.
(5) from the parametric study of Bangkok, it observed the following
• The maximum rate of increase in lateral deformations between no temperature and temperature change (-35 ˚C) is + 32%. Also, The maximum rate of increase in the vertical settlement between no temperature and temperature change (-35 ˚C) is + 26%. Based on the results, it was concluded that the thermal effect on the analysed wall deflection and ground movements of concrete floor slabs had a considerable influence.
• The relationship between temperature changes (ΔT) and the lateral wall deformations (δhm) is approximately linear.
• The relationship between temperature change (ΔT) and the vertical soil settlement of soil (δvm) is approximately linear.
• The relationship between the maximum vertical settlements and the lateral wall deformations (δvm/δhm) give values equals 0.8 to 1.2.
• The wall deformation is decreased by -50% with the increase of wall stiffness. Also, the increase in wall thickness has reduced the ground settlement by -38%.
• The relationship between the change of lateral wall deformations and the wall thickness is approximately linear but with different slopes. The same relationship between the change of ground settlement and wall thickness.
• It is concluded that the effect of length has a minor impact on the first stages of excavation on wall deformations. However, it has a significant impact on the final phase of excavation as with increasing the wall length; the deformation is reduced by -36%.
• The vertical settlements of the soil increase with the decrease of wall length. However, the vertical settlement of the soil increases with the increase of wall length after a turning point. The distance of turning point from the wall almost equals the excavation depth. We can also find after 30m of length the deformation and settlement will decrease with small values.
• By increasing the wall length, the distortion angle is reduced that shall have an impact on building beside excavation if it existed.
• The deformations shall not increase and considered constant when the ratio between the wall length and the excavation depth is more than 1.4.
(6) from the comparison between different constitutive models, The Mohr-coulomb model gives values of deformations higher than the values from the modified Mohr-Coulomb; conversely, the hardening soil model gives values of deformations compatible with Modifies Mohr-Coulomb model. The lateral deformations from Hardening soil small strain model are near to the deformation of the Hardening soil model.
(7) The Soft Soil model is an important model to consider, especially for soft soil. from Surarak (2011), the soil model Parameters were obtained from the consolidation characteristics of the Bangkok clays give higher deformations than the soft soil Parameters calculated from the loading stiffness E50 by using (Finno and Calvello 2005) approach. The soft soil Parameters calculated from the loading stiffness E50 by using (Finno and Calvello 2005) approach give a close value of wall deformations to the measured values.
(8) Two cases of top-down construction and down-top construction were analysed in port-said soil to conclude the results of lateral deformations and ground settlement. The results from analyses of the top-down model and down-top model were compared with the empirical method; it can be concluded the following.
For the down-top model and top-down model, the vertical settlement values from the analysis have a good agreement with Zapata 2007 and Clough and O’Rourke 1990, respectively.
For the down-top model and top-down model, the analysed lateral deformations values have a good agreement with Long, 2001, Clough et al. (1989), and Zapata-Medina (2007) by using Ukritchon et al. (2003) factor of safety (FS) against basal heave.
7.3 Recommendation for Future Research
The following topics are suggested for future research projects relevant to the subject of this investigation:
(1) Performing three-dimensional finite element analysis using the hardening soil model to verify the plane strain finite element analysis.
(2) Investigating the influence of adjacent buildings loads and location on the deformation of the shoring system in soft clay.
(3) Investigating the effect of adjacent buildings loads and location on settlement influence zone.
(4) Construction time effect in the wall deformations and ground settlement.