- Slope Stability, Triggering Events, Mass Wasting Events SLOPE MOVEMENT AND MASS WASTINGS: A CLASSIFICATION OF MASS MOVEMENT - Slope Stability, Triggering Events, Mass Wasting Events Types of Slopes: - Natural Slopes -- Valley Sides -- Hill Slopes -- Coastal Slopes -- River Banks , etc.

.. Foundation Excavations .. Road cuts/Highway Slope - Man-made Slopes .. Excavations .. Open Cast Mines .. Quarry Sides .. Deep Trench .. Foundation Excavations .. Road cuts/Highway Slope .. Embankment slopes -- > Roads , Dams, etc.

a) Based on Nature of Movement: A CLASSIFICATION OF MASS MOVEMENT a) Based on Nature of Movement: - Rapid movement . Fall . Slide . Flow . Collapse - Slow movement . Creep . Subsidence (settlement) b) Based on Nature of Materials

.. Creep True creep Rock Soil . Avalanche Debris . Fall Water . Slide Ice(snow) . Flow Slow Movement : .. Creep True creep Seasonal creep

. Mining activity / tunneling activity - Subsidence (settlement) : vertical mass movement - Collapse or sink Subsidence : . Mining activity / tunneling activity . Petroleum extraction , solution mining . Groundwater extraction . Solution effects Rapid Movement: . Fall . Rotational(circular) . Slide . Translational(planar) . Flow LANDSLIDES . Rock, earth, debris slumps

CLASSIFICATION OF LANDSLIDES: Earth . Fall Mud . Flow Debris Rock CLASSIFICATION OF LANDSLIDES: . Based on Water Content (liquidity index) . Based on Mechanism of Slides (Geomechanical Classification) . Based on Geometry of the Slip Surface

. Flow slide : Very high moisture content/ มักเกิดหลังฝนตกหนัก - Classification Based on the Water Content of the Materials forming the Slope (Liquidity index): . Flow slide : Very high moisture content/ มักเกิดหลังฝนตกหนัก . Mud slide : Translational type of sliding/เกิดในวัตถุพวก fine grained soils (mud) และมักพบตามพื้นที่ชายฝั่งทะเล . Landslides : ดูในหัวข้อ Landslides . Rockslides : แบ่งออกเป็น Block slides (planar slide) และ wedge slides . Toppling : rotational of column / block about a fixed base.

.. Circular slips occur in very uniform homogeneous soils. - Based on Geometry of the Slip Surface : .. Circular/rotational slides / เกิดในพื้นลาดที่เป็น Uniform homogeneous Soils. .. Circular slips occur in very uniform homogeneous soils. .. Circular / multiple rotational slides .. Non-circular slide .. Planar slide .. Wedge slide - Landslides Based on Mechanism of the Slides (Geomechanical Classification) .. Not considered in this lecture.

Factors Influencing Landslides External Causes Internal Causes . Increasing driving forces . Decreasing resisting forces . Steepening slope angle by . Increase pore erosion (natural & man-made) pressure . Progressive decrease . Increasing load of cohesion ( C ) of material forming . Traffic vibration/blasting the slope. . Earthquakes . Subsurface weathering . Rainfall (increasing pore . Lubricating effects Pressure) (H2O) . Capillary force (unsaturated . Rapid draw-down soil slope) . Seepage forces

เกิดโดยมวลหินหลุดร่วง หรือล้ม (topple) SLOPE FAILURE : - Detachment of rocks --- > Rock falls เกิดโดยมวลหินหลุดร่วง หรือล้ม (topple) - Shear Failure /การพังทลายที่เกิดบนพื้นลาดที่มีมวลขนาดใหญ่และเป็นปริมาณมาก - Creep / การเคลื่อนตัวแบบคืบ เกิดจากการปรับตัวอย่างช้าๆของวัตถุบนพื้นลาด

Landslides Hazards:

Highway Slope Failure

Road Embankment Failure.

Debris Flow , Nam Ko , Petchaboon.

Debris Flow , Nam Ko , Petchaboon.

Valley slope Failure

Coastal Slides End