The Primary Research Of The Forecast Model Of The Source Area's Soil Starting For The Soil-Mechanical Debris Flows

Debris flow is the familiar nature disaster in mountainous region. It is the saturated fluid that slope deposit interblends with water under the gravitational function sports along abrupt slope or ditch. It brings mountain area people the heavy disaster with its paroxysmal, night occur, part ground, impermanency, tremendous force. Along with the development of the social economic activities, the human unreasonable activity increases, the ecosystem environment is worsened. It accelerates the formation of the debris flow. Our country with debris flow disaster seriously, developing debris flow study to forecast the early warning, prevent and cure debris flow availably is very necessary. In this order, that, study of the formation mechanism of soil-power type debris flows, evaluating Method for the type of rainstorm slope debris flow starting, establishing the of slope debris material loses the steady evaluating system, the research meaning is marked.This paper rounds the soil-mechanical debris flow's mechanism of starting and its evaluating method for predicting, the main study includes the following: (1) Study the mechanism of rain producing flow on the slope, using the ability curve of that rainfall penetrates below the surface of the ground to deduce a calculation method for raining producing flow on the slope. It can calculate how much the rain producing surface water and groundwater on slope, and the rain influences deposit with the moisture content variety on slope. (2)On the foundation of previously plentiful experiments data, study the relation between the shear strength indices of the cohesion C and friction angle and the moisture content of slope deposit, deduce the method of calculation the stability coefficient of debris deposit that considering the effects factors of surface flows, the underground seepage, and the force of seepage, the static hydraulic pressure, the force of raindrop shot on the surface ground etc. It clarifies the steady mechanism and evaluating the method of slope deposit. (3) Establish the effective debris deposit concept. And on this foundation establish the model for forecasting the soil-mechanical debris flow starting, that model using of the soil mechanics knowledge, analyzing debris slope deposit suffering force on the half infinite long slope, deducing the slope soil- mechanical debris flow starting critical condition ground on the gradually soakage saturated depth in rain process, and analyzed several specially debris deposit forms on slop starting critical condition, then fetch up the model shortage. (4)On the foundation of the before experiment data, making use of the soft of VB6.0 to gather with the soft Excel to development the system for evaluating debris deposit stability ground on the soil mechanics principle, that system can be able to deal with the reconnaissance data of debris deposit on the slope, and to use of three turn corner equation to match the data three times kind a curve, and to calculate the real-time quantity of the surface flow and ground flow produced by rain, and evaluating debris deposit stability real-time, for the soil-mechanical debris flow forecast offering the theory.