Analysis of a deep excavation in Shanghai soft clay
A deep multistrutted metro station excavation in Shanghai soft clay was reanalyzed with the DeepEX software program. The observed responses of the diaphragm walls and the ground surface were originally presented in a paper by G.B. Liu & J. Jiang from Tongji University, Shanghai, China and C.W.W. Ng from the Hong Kong University of Science and Technology, HKSAR.
EXCAVATION MODEL
In the original publication, the measured diaphragm wall deflections and ground settlements were compared with some case histories in Shanghai and excavations in soft clay in other locations in Asia. The purpose of this analysis is to reanalyze the model with DeepEX software and compare the program estimated results with the presented measured deflections.
Figure: Cross section 1-1
Surface El: +3.7 m , Water Table El: +2.7 m
SOIL CONDITION
Figure: Soil profile in publication
Table: Assumed soil properties in deep excavation reanalysis
STRUCTURAL PROPERTIES
Figure: Wall Properties
Figure: Support Properties
MODEL IN DEEPEX
We have simulated this excavation model with our shoring design software program, DeepEX. In DeepEX we can simulate all construction stages in the same project file, so we can monitor and analyze each stage. The following figure presents the final excavation stage.
Figure: Model Simulated in DeepEX
According to the original publication, there is a 3m compaction grouting below the final excavation to increase the soil strength in this part. We simulated this compaction grouting in DeepEX by assigning a soil change command, that allowed us to apply a stiffness multiplier in all stages on the resisting side (excavation side).
Figure: Soil Change Commands in DeepEX – Assign Stiffness Multiplier
WALL DEFLECTIONS
The Nonlinear analysis in DeepEX software estimates a maximum wall displacement of 5.03 cm in the final excavation stage. The following figure presents the calculated wall moments and wall deflection diagrams.
Figure: DeepEX – Final Excavation Depth – Calculated Wall Moments and Wall Deflections
According to the original publication, seventeen inclinometers were used to monitor lateral wall displacements. The maximum measured wall displacement at the final excavation depth (see following figure) was 5.45 cm, verifying the DeepEX calculated wall lateral deflections!
Figure: Maximum Measured Wall Displacements at Final Excavation Depth
Interested in More?
Book a FREE online presentation now!
DeepEX - Shoring Design Software
DeepEX is the ultimate software program for design and analysis of Deep Excavations! Design any wall type and support system in the most efficient way!
|
|
|
|
|
|
DeepEx Demo
Structural and Geotechnical design of Deep Excavations.
Try the Full version for free and see how you can design and optimize any deep excavation model in the most efficient way!
Starting at
$ 3750
Web Presentation
Get a Free online presentation! Learn about all software features and capabilities!
Purchase DeepEX
Get the most powerful shoring design software! Customize your version!
Software
Review our software programs for geotechnical engineers and contractors!
DeepEX Features
All software features and capabilities! Review all available design methods and analysis standards!
DeepEX Upgrades
We continue our research and we introduce new unique features that extend the software capabilities!
HoloDeepEX
Export and visualize 3D deep excavation models in Virtual and Augmented Reality! Impress your clients!
Trusted by
