五、 Soil tillage resistance (-- Soil resistance 垂直荷载 to compression and 水平力 to penetration 上盒 (二) Soil draft resisting force 剪切面土样 下盒 图12-10土样在剪切盒中受力情况五、Soil tillage resistance （一）Soil resistance to compression and to penetration （二）Soil draft resisting force