| | Scheme | Condition | Description |
| | 1 | Initial state | The effects of reservoir impoundment and rainfall were not considered. The water level of the Qinggan River was 90 m. The state expressed in this scheme was the initial state of the slope before reservoir impoundment. | | 2 | Reservoir impoundment | The water level of the Qinggan River rose from 90 to 135 m in 15 days (May 27, 2003–June 10, 2003) with a rate of 3 m per day and maintained at a constant value of 135 m for 33 days (June 10, 2003–July 13, 2003). In this scheme, the interlayer staggered zone, the gently dipping discontinuous structural plane, and the rock mass at the toe of the slope were submerged by the reservoir water [10, 13, 14]; therefore, their physical and mechanical parameters below the reservoir water level changed from the natural state to saturated state (values of modulus of elasticity, friction angle, and cohesion changed from A column to B column in Table 1) in this scheme. | | 3 | Rainfall | The water level of the Qinggan River maintained at 90 m, and the rainfall process lasted 22 days (June 22, 2003–July 13, 2003, shown in Figure 5). Because intermittent rainfall was difficult to make the rock mass saturated, in this scheme, strength parameters of the rock mass were not weakened; values of modulus of elasticity, friction angle, and cohesion were designated as values in A column of Table 1. | | 4 | Reservoir impoundment and rainfall | This scheme was divided into two stages. At the first stage, from May 27 to June 10, 2003, the water level rose from 90 to 135 m and then maintained at 135 m to June 21, 2003. At the second stage, from June 22, 2003, to July 13, 2003, the reservoir water level maintained at 135 m, and the slope underwent the rainfall process (Figure 5). In this scheme, the toe of the slope was affected by reservoir impoundment; the values of modulus of elasticity, friction angle, and cohesion of the rock mass changed from the natural state to saturated state the same as scheme 2. |
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