CIE3032 지반공학및실험 lecture 03 lateral earth pressure 1

LECTURE 03

Lateral earth pressure

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 2

Curved failure surface

Shear forces that develop at the wall-soil interface causes the failure surface to become curved

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 3

Log-spiral

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 4

Rankine zone

Radial shear zone

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 5

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 6

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 7

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 8

Additional concerns

Effect of water table

Effect of surcharge

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 9

Calculation of passive earth pressure

qKp

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 10

Failure modes

Overturning

Sliding

Slope failure

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 11

Braced cuts (excavation)

Provides temporary support during excavationA typical braced cut consists of sheet piles, wales, and strutsNeed to design the structural elements / spacing / intervalNeed to know the lateral earth pressure

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 12

Earth pressures

Difference between failure modes of retaining walls and braced excavation: Failure as a single unit (simultaneous) vs. Progressive failureEmpirical earth pressure (Peck, 1969)

CIE3032 지반공학및실험 lecture 03 lateral earth pressure 13

Braced cuts (excavation)

Calculation for the strut load: assume struts are connected by hinges except for top and bottom struts (fixed)

Example 14.2