2. §6 Earth Pressure and Retaining Wall 土压力理论与挡土墙设计 Introduction/ 引言 Rankine’s earth pressure theory / 朗肯土压力理论 Coulomb’s earth pressure theory / 库仑土压力理论 Discuss / 讨论 Retaining wall design / 挡土墙设计

3. 6.1 Introduction/ 引言 -Coefficient of earth pressure at rest 主动土压力 被动土压力 静止土压力

4. 6.2 Rankine Earth Pressure theory / 朗肯土压力理论 6.2.1 Limit state/ 极限状态 -Active limit equilibrium/ 主动极限平衡 -Passive limit equilibrium/ 被动极限平衡

5. 6.2.2 Rankine active earth pressure/ 主动土压力 In Non-Cohesive soils (soil surface horizontal)/ 地表水平无粘性土

7. In Cohesive soils (soil surface horizontal)/ 地表水平粘性土

8. For sloping soil surface(β) / 地表倾斜

9. 6.2.3 Rankine passive earth pressure/ 被动土压力 In Non-Cohesive soils (soil surface horizontal) / 地表水平无粘性土

10. In Cohesive soils (soil surface horizontal)/ / 地表水平粘性土

11. 6.3.1Basic concept -Assuming -Active earth pressure 6.3 Coulomb’s Earth Pressure theory / 库仑土压力理论 -Passive earth pressure

12. 6.3.2 Active Case/ 主动情形 General solution

13. If i=0,α=0,δ=0, Then

14. Complex boundary conditions/ 复杂边界条件

15. -Coefficient of active earth pressure / 主动土压力系数 λ a

16. -Distribution of active earth pressure / 土压力的分布

17. -Example A retaining wall of embankment is 6m high. And the relative parameters are c=0,φ=30 。,α=14 。 00’,δ=φ/3, as well as shown in Fig. below. Calculate the active earth pressure and draw the distribution.

18. -Solution ① Assuming sliding surface is BC

19. ② Verifying sliding surface location So, The Sliding surface agrees with the assumption. ③ Calculate the Coefficient of active earth pressure λa ④ Calculate the active earth pressure Ea and its distribution

20. ⑤ Draw the distribution of the active earth pressure

21. 6.3.3 Passive Case

22. If i=0,α=0,δ=0, Then 6.4 Discuss 6.4.1 Equivalent internal friction angle

24. 6.4.2 Several-layer soils

25. 6.4.3 wall back in polygonal line

26. 6.4.4 graphical method

27. 6.4.5 Earth pressure of abutments