	US 12,106,020 B2
	Dynamic prediction method and system for initiation volume of debris flow slope source
Yuanjun Jiang, Chengdu (CN); Xiaobo Hu, Chengdu (CN); Lijun Su, Chengdu (CN); and Xin Xia, Chengdu (CN)
Assigned to INSTITUTE OF MOUNTAIN HAZARDS AND ENVIRONMENT, CHINESE ACADEMY OF SCIENCES, Chengdu (CN)
Filed by Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu (CN)
Filed on Jun. 7, 2021, as Appl. No. 17/341,275.
Claims priority of application No. 202110030645.X (CN), filed on Jan. 11, 2021.
Prior Publication US 2022/0222393 A1, Jul. 14, 2022
Int. Cl. G06F 30/20 (2020.01); G06F 17/18 (2006.01); G06F 111/10 (2020.01); G06F 111/08 (2020.01)

CPC G06F 30/20 (2020.01) [G06F 17/18 (2013.01); G06F 2111/08 (2020.01); G06F 2111/10 (2020.01)]

8 Claims

1. A prediction method for an initiation volume of a debris flow slope source, wherein the prediction method comprises:

selecting a debris flow source slope to be predicted, and dividing the debris flow source slope to be predicted into regular hexagonal soil columns arranged in i rows and j columns;

calculating a most unfavorable sliding surface of each soil column according to an upper bound theorem of a limit analysis, and calculating an unbalanced force on the most unfavorable sliding surface; wherein the most unfavorable sliding surface represents a sliding surface with a lowest stability coefficient along a depth of the soil column;

determining whether each soil column is unstable according to the unbalanced force on the most unfavorable sliding surface; stopping the prediction of the soil column if a determination result indicates no, and if the determination result indicates yes, then

acquiring centers of gravity and elevations of a central soil column and six adjacent soil columns around, determining an instability direction of the central soil column, and determining a force mode of the six surrounding adjacent soil columns on the central soil column;

simulating the force mode of the six surrounding adjacent soil columns on the central soil column through a fiber bundle model, and determining a break status of connection bonds; stopping the prediction of the soil column if a determination result indicates that connection bonds of a lateral tensile stress are not all broken, and if the determination result indicates that the connection bonds of the lateral tensile stress are all broken, then

determining whether the soil column is fluidized according to a fluidization criterion; stopping the prediction of the soil column if a determination result indicates no, and if the determination result indicates yes, predicting that the soil column is about to initiate a debris flow, and predicting an initiation volume of the debris flow slope source according to a fluidization status; and

taking engineering measures to prevent and control disasters based on the predicted initiation volume, wherein the engineering measures comprise:

determining an engineering prevention level, and rationally designing a size and quantity of a blocking dam and drainage channel so as to reduce the waste of resources caused by unreasonable engineering design;

setting a debris flow initiation volume-induced disaster threshold or level, realizing an early warning and forecast of the debris flow before the initiation volume reaches the disaster threshold or level, and evacuating affected people in time; or

determining the location and scale of the debris flow after the debris flow occurs, planning rescue implementation plans, and carrying out rescue and dredging operations;

wherein the acquiring centers of gravity and elevations of a central soil column and six adjacent soil columns around, determining an instability direction of the central soil column, and determining a force mode of the six surrounding adjacent soil columns on the central soil column specifically comprises:

acquiring a position (i,j) of the central soil column, and determining the center of gravity of the central soil column as (x_i,j, y_i,j, z_i,j);

determining, according to the position coordinates of the soil columns and a geometric principle, the center of gravity of the surrounding adjacent soil column as (x_k,y_k,z_k) (k=0,1,2,3,4,5,6):

acquiring, according to the center-of-gravity coordinates of the central soil column and the surrounding adjacent soil column, a vector of the surrounding adjacent soil column relative to the central soil column, (x′_k,y′_k,z′_k),

wherein L_grepresents a spacing between adjacent soil columns;

determining a sum vector of two adjacent soil columns among the surrounding soil columns as (x′_k,k+1,y_kk+1,z_k,k+1):

determining a projected vector of the sum vector in a two-dimensional plane as D_k,k+1(k=0,1,2,3,4,5);

determining a sum vector with a lowest center of gravity min(z′_k,k+1) (k=0,1,2,3,4,5) as a movement direction vector of the soil column according to a principle of least action;

calculating, by taking a value of k in the case of min(z′_k,k+1) (k=0,1,2,3,4,5), the projected vector of the movement direction of the central soil column in the two-dimensional plane as (x″_i,j,y″_i,j):x″_i,j=x′_k,k+1, y″_i,j=y′_k,k+1;

determining a projected vector of a movement direction of the surrounding soil column in the two-dimensional plane as (x″_k,y″_k);

determining an angle θ_kbetween adjacent soil columns,

determining, when an angle between movement direction vectors of adjacent soil columns is an acute angle, that a force between the soil columns is a compressive stress; determining, when the angle between the movement direction vectors of the adjacent soil columns is an obtuse angle, that the force between the soil columns is a tensile stress;

wherein, if

then τ′_Tk=−τ_Tk;

then τ′_Tk=0;

then τ′_TK=τ_Tk;

τ_Tkrepresents a force exerted on the central soil column by a surrounding soil column that is unstable;

T′_Tkrepresents a force exerted on the central soil column by the surrounding soil column, which is used to calculate a sliding force.