Retaining of Deep Excavation
Excavation dimensions:
32m by 47m in-plan and depth of 11.5m
Retaining structure: 3000 m2 of soil mixing secant wall (SCM) columns with diameter of 700 mm and length of 17 m length, 50 cm center to center distance); Primary SCM panels are non-reinforced whereas secondary SCM panels are reinforced by H-BEAM steel profiles; The retaining structure is horizontally supported by 3 rows of self-drilling anchors and RC cap beam on the top level of the soil-mix wall.
Unconfined compressive strength of soil-mix material:
8.6 MPa
Water level:
2.90 m below ground level
Dewatering:
Gravity drainage and dewatering system which consists of 6 wells
Dewatering:
Soil mixing wall dimensions have been verified by core drilling; Samples have been extracted and tested in the lab for the sake of determining unconfined compressive strength and modulus of elasticity of the soil-mix material; Anchor load tests have been performed for verification of bearing capacity; Anchor forces are controlled by means of electrical load cells; Topographic survey is performed through setting optical targets in order to evaluate horizontal displacement of the retaining structure during construction.