# Q7A · Explain in detail Cause, Characteristics and Mitigation measures for “Topple” type of…

Subject: Disaster Management

Exam: TEE

Reader: https://deep-learning-study-room.vercel.app/dm/#tee/papers/paper-2026-02-12/q7a

Canonical: https://deep-learning-study-room.vercel.app/read/dm/tee/papers/paper-2026-02-12--q7a/

Actual TEE paper · 100 marks · 3 hours · Q1 + any four of Q2–Q7

### Q7A. Explain in detail Cause, Characteristics and Mitigation measures for “Topple” type of Landslide. [10 marks]

#### Answer

A **topple** is the forward rotation of a rock or soil mass out of a slope about a pivot near its base. It differs from a slide, in which a mass moves along a rupture surface.

Swipe across the diagram to read its labels ↔

![Landslide mechanisms require different solutions](https://deep-learning-study-room.vercel.app/dm/fig/slope.38d4f3b001.svg)

Diagram: Landslide mechanisms require different solutions. Labels: Landslide mechanisms require different solutions | Landslide mechanisms require different solutions | Rotational slide | Topple | Curved slip surface | Drainage / stabilisation / safer siting | Block rotates forward | Assess joints, toe support and water | Measures must follow site investigation; vegetation alone does not stop every failure.

The right-hand sketch shows a block rotating forward: a topple.

## Causes and characteristics

1. **Fractured structure.** Steeply jointed or layered rock can form columns or blocks with limited lateral support.
2. **Loss of support.** Erosion or excavation at the toe can remove resistance and allow forward rotation.
3. **External triggers.** Water pressure, weathering, freeze-thaw where applicable or earthquake shaking can destabilise blocks.
4. **Visible behaviour.** Leaning blocks, opening joints and detached fragments may indicate instability. Movement may involve individual blocks or a larger interacting mass.

## Mitigation

1. **Investigate and restrict exposure.** Map unstable rock and keep buildings, parking and people away from the potential fall/runout zone.
2. **Improve drainage.** Control infiltration and pressure through professionally designed drainage.
3. **Stabilise or remove hazardous material.** Suitable anchors, bolts, support or controlled scaling require specialist design and trained execution.
4. **Protect and monitor.** Use designed catch structures where appropriate; monitor movement and close threatened routes when necessary.

#### Illustrative application · A road cut after prolonged rain

Removing support at the base of a slope and allowing water to enter can reduce stability. An appropriate response investigates ground conditions, improves drainage and uses engineered support or safer siting. The correct design is site-specific, not a universal wall for every slope.