JP2006252128A - System for predicting slope collapse and for transmitting evacuation information to peripheral area - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for predicting slope collapse and for transmitting evacuation information to a peripheral area, setting a collapse safety ratio in a slop to be targeted according to a change of a water level instead of grasping a displacement state of the slope to be monitored as measurement of displacement data, simply performing collapse prediction of the slope from soil properties of the slope and a change of a groundwater level accompanying rainfall, and allowing rapid and efficient transmission of an analysis result thereof to the peripheral area via a transmission means such as the Internet by use of a held map database of GIS. <P>SOLUTION: This system has: a collapse safety ratio curved surface database section; an analysis section for performing penetration flow analysis on the basis of precipitation of each the targeted slop obtained in time of the rainfall to find a water head change in time of the rainfall; an evaluation section comparing a safety ratio curved surface stored in the collapse safety ratio curved surface database section and a water head in time of the rainfall to perform collapse safety ratio evaluation of the monitoring target slop; and a display transmission means displaying and transmitting safety action information of a resident of the peripheral area based on situation prediction of the monitoring target slop predicted from an evaluation result thereof. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a slope failure prediction and an evacuation information transmission system to surrounding areas. In order to quantitatively evaluate the risk of slope failure such as steep slopes during rainfall, and to prevent damage to residents due to slope failure, slope failure The present invention relates to a slope failure prediction and an evacuation information transmission system to the surrounding area, which can accurately provide information such as caution, warning and evacuation in the surrounding area.

  In Japan, there are many steep landforms, and in the past, there has been a lot of damage caused by collapse of steep slopes along with inundation damage in lowland areas as a rain disaster. At present, each local government designates a steeply sloped danger area, regulates the building, and considers the safety of residents in such an area. And the possibility of slope failure (damage) based on the total amount of rainfall from the beginning of the fall and the progress of slope deformation, and attention, warning or evacuation recommendations for residents in the surrounding area, Measures are taken to transmit evacuation information corresponding to the expected damage scale and level of evacuation orders (hereinafter referred to as evacuation information). However, the judgment of these evacuation information is often based on comparison with past occurrence data and empirical rules, and measurement data can be processed and examined for sudden changes in weather or heavy rains exceeding the predicted rainfall. There is a problem that accurate judgment cannot be made because it is not in time or the criteria for determination are not clear.

  There is an invention disclosed in Patent Document 1 as a prior art that solves such a problem. The present invention processes position information of a slope to be monitored (measured) as high-precision GPS data, obtains slope state data (for example, displacement) of the area, and further measures actual rainfall data and prediction indicating rainfall. Using rainfall data as meteorological data, quantifying weather data, slope condition data and slope failure risk, creating a database, predicting the occurrence of slope failure in the target area, and evacuating information as necessary Is coming out. Each data is updated sequentially, and evacuation information is provided based on the latest situation.

  In the computer system of the present invention, slope displacement data is obtained at predetermined time intervals using the reference point position information and other position information, and the slope displacement data is obtained by setting the horizontal axis as time and the vertical axis as displacement. And is stored in the database for each slope. In addition, since the slope displacement data includes various external factors, it is difficult to accurately grasp and evaluate the state of the slope from such slope displacement data. Therefore, in the present invention, the slope displacement data is filtered and smoothed to generate processed displacement data, which is used as state grasping data. From the processed displacement data, the displacement amount and displacement speed of the slope Then, the displacement acceleration is obtained and the displacement amount of the slope is predicted.

  The rain gauge measures the rainfall for each slope or receives the rainfall data and stores it in the database as meteorological data, and also stores the predicted rainfall data in the database. The database stores basic information and processing for each slope. Displacement data (measurement results), remote sensing data, and meteorological data are accumulated, and multivariate analysis using these multiple data as variables is performed to obtain a collapse risk score value.・ Evacuation / road regulation standards) are set and updated.

Japanese Patent Application Laid-Open No. 2004-280204.

  The invention of Patent Document 1 described above acquires data such as slope displacement as high-precision GPS data, performs quantitative statistical processing together with rainfall data at the location, and quantitatively grasps the risk of the slope. , Warning and evacuation orders can be set and updated accurately. However, the data type is equivalent to the amount of rainfall that has hitherto been handled on the slope and the displacement state of the target slope at the time of rainfall. In the processing of these data, there is a feature in that the relation of the data is made highly accurate and quantitative judgment criteria are applied, but basically, as in the prior art, the displacement state of each slope is continuously maintained. Measurement is required. For this reason, in order to perform wide-area slope failure prediction, it is necessary to set equipment such as a GPS reference station on all slopes to be monitored. For this reason, the cost of system facilities becomes enormous.

  By the way, in recent years, many plans are being promoted by local governments and the like to promote the creation of a local disaster prevention plan database using a geographic information system (hereinafter referred to as GIS). Specifically, a hazard map or the like has been prepared in advance to understand vulnerability to disasters in areas designated as steep slope collapse risk areas. However, at present, the actual situation is that it is only used as fixed information data for browsing a statistical map database or the like. Therefore, the basic geographic information data based on these databases is mapped to the basic geographic information data on the server managed by the local government by processing and mapping information on the risk of slope failure during rainfall, via the Internet, etc. If it is possible to respond to inquiries about the situation from residents as visual information, it can function as an effective evacuation information transmission means for residents in the surrounding area such as the slope collapse risk area.

  Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art and not to detect the displacement state of the slope to be monitored as measurement of displacement data, but to calculate the safety factor of collapse on the slope to be measured as the water level. It is set according to the change of the slope, the slope collapse is easily predicted from the soil soil properties and the change of the groundwater level due to rainfall, and the analysis result is obtained using the map database of GIS. Another object of the present invention is to provide a slope failure prediction system and an evacuation information transmission system to the surrounding area which can be quickly and efficiently transmitted to the surrounding area through a transmission means such as the Internet.

  In order to achieve the above-mentioned object, the present invention performs the osmotic flow analysis based on the precipitation safety factor curved surface database section and the precipitation of each slope to be monitored obtained at the time of rainfall to determine the head change at the time of the rain. The analysis unit to be calculated, the safety factor curved surface stored in the collapse safety factor curved surface database unit, and the evaluation unit that evaluates the collapse safety factor of the monitored slope by comparing the rainfall head with the rainfall head, and predicted from the evaluation result And a display transmission means for displaying and transmitting the safety behavior information of residents in the surrounding area based on the predicted situation of the slope to be monitored.

  The collapse safety factor curved surface is composed of a curved surface data group created from the relationship between the inclination angle of each slope to be monitored, the constant water level of the slope to be monitored, and the collapse safety factor. It is preferable to keep it.

  It is preferable that the evaluation result is plotted on a digital numerical map provided in the display transmission means, and the evaluation result is updated and displayed on the digital numerical map in accordance with a change with time of rainfall.

  It is preferable that the display transmission means is a website on the Internet, a cable TV, or a wireless transmission device, and that residents in the surrounding area can always access as the rainfall changes with time.

  According to the present invention, in order to quantitatively evaluate the risk of slope failure such as steep slopes during rainfall, and to prevent damage to residents due to slope failure, the surroundings against slope failure using the Internet and other information transmission means There is an effect that it is possible to accurately provide information such as caution, warning and evacuation in the area.

  Hereinafter, as the best mode for implementing the slope failure prediction and evacuation information transmission system to the surrounding area of the present invention, the following embodiments will be described with reference to the accompanying drawings.

  FIG. 1 shows the safety of a slope to be monitored based on the safety factor obtained by analyzing the change in the water level of a slope during rainfall in the slope failure prediction and evacuation information transmission system of the present invention. It is the flowchart which showed an example of a series of work procedures until it evaluates and transmits the result as safety action information etc. to the residents of the surrounding area.

In the present invention, for example, in a certain local government, a slope that has a possibility of slope failure and that is designated as a steep slope failure danger area is selected and all the selected slopes are monitored. set to target. Then, the collapse safety factor curved surface data in which a unique safety factor F _s is set according to the state of each slope is created.

As shown in FIG. 2, the collapse safety factor curved surface data includes three variables representing changes in the safety factor F _s with respect to the slope inclination angle α as the ground characteristic of the slope and the water level h within a predetermined range as the rainfall characteristic. It is calculated as a relational curved surface consisting of The safety factor F _{s at} this time is calculated as a ratio between the target soil mass self-weight that has been conventionally used in the arc slip analysis and the slip resistance at the arc slip surface as shown in (Equation 1). As a characteristic of (Formula 1),

…（式１）
ここで、τ_f：破壊面のせん断強度、
τ ：破壊面のせん断応力
σ_f：破壊面上の破壊時直応力
ｃ’：粘着力
φ’：内部摩擦角
ｕ：水圧

... (Formula 1)
Where τ _{f is} the shear strength of the fracture surface,
τ: Shear stress of fracture surface
σ _f : direct stress at failure on the fracture surface
c ': Adhesive strength
φ ': Internal friction angle
u: Water pressure

The safety factor F _s at the constant water level for each slope is made into a database and plotted as a constant safety factor region on a raster map image such as a numerical map 25000 as digital map information issued by the Japan Map Center. The slope failure safety factor distribution map can be created. This can be a basic information map (FIG. 3) of the hazard map of the geographic information system (GIS) promoted by local governments. FIG. 3 illustrates, as an example, a hazard map in which the equal safety factor line area of the collapse safety factor on the target slope is a closed curve and the safety factor within that range is numerically displayed.

This basic information map is preferably updated with the evaluation of the safety factor F _s by a periodic groundwater level survey or the like. Thus, by setting the hazard map of GIS to the state of the latest information on the server, it is possible to accurately determine the safety when the monitored slope is raining.

  Next, if there is rainfall that would cause slope failure in the area including the monitored slope, the finite element with the water level change on the monitored slope as the governing equation based on the amount of rainfall. Calculate by performing legal analysis. As for the rainfall at this time, it is preferable that automatic measurement data collected by a self-recording rainfall meter installed in the field is collected by wireless means or wired and used as it is. In addition, for example, if it is an area where specific area information of AMeDAS information provided by the Japan Meteorological Association can be obtained, it is possible to download and use rain data by that AMEDAS sequentially.

…（式２）
ここで、Ｋ_x，Ｋ_y，Ｋ_h：監視対象斜面の地盤のｘ，ｙ，ｚ方向透水係数
Ｓ_s：比貯留係数
ｈ：水頭（水位）（ｍ）
Ｒ^*：一般的吸い込み項、あるいは沸き出し項

... (Formula 2)
Where K _x , K _y , K _h : Permeability coefficient in the x, y, z direction of the ground on the slope to be monitored S _s : Specific storage coefficient h: Water head (water level) (m)
R ^* : General suction term or boiling term

FEM unsteady seepage flow analysis is performed using the rainfall on the monitored slope at the time of rainfall as an input value, the osmotic flow equation of equation (2) as the governing equation, and the monitored slope as a three-dimensional finite element model. Specifically, substituting real-time rainfall on the monitored slope into the boiling term R ^* in (Equation 2), under boundary conditions that take into account changes in the free water surface, etc. on the monitored slope Solve (Equation 2). As a result, the water head h after the change on the slope to be monitored according to the rainfall at that time can be obtained. Note that in the finite element model of the slope to be monitored, the saturated / unsaturated seepage flow analysis may be performed with the analysis target region taken into consideration. In the selection of these finite element models, the number of elements, the analysis range, and the boundary conditions may be determined in consideration of the cost effectiveness of the analysis time (cost) and the obtained analysis results.

  Disaster prevention organizations such as municipalities, for example, have a hazard map as a server for the slope failure safety factor of the target slope that changes based on the continuous analysis results (water head h after water level change) obtained with changes over time in rainfall. The above is sequentially updated (see FIG. 4). Also, based on this latest information, the disaster prevention organization, in accordance with the displayed collapse safety rate, provides the level of safety action to be taken by residents in the area surrounding the target slope, along with providing numerical information on the hazard map, Communicate to the residents. For example, if the amount of rainfall increases rapidly and the safety factor of the slope to be monitored declines rapidly on the hazard map, the latest information updated on the server is constantly connected to the surrounding residents. It is displayed on the website (WebGIS system) by, or continuously broadcast by the disaster prevention channel provided in the local cable TV, and the safety status of the monitored slope that changes from moment to moment is communicated to the residents.

  In addition, as a safety action standard that should be set in advance and communicated to the residents, examples of the standard level of this safety action include, for example, warnings, warning warnings, evacuation preparation recommendations, evacuation recommendations, forced evacuation orders according to the weather forecast. For example, information that matches the decline in the safety factor of the slope to be monitored can be assumed. Similar to the hazard map, these safety behavior information is transmitted, as shown in FIG. 5, for example, as an example of the screen display example 2 of the safety behavior information as information that should be taken by residents through the Internet or cable TV disaster prevention channels. can do.

  In addition, it is preferable that the above-mentioned analysis of data such as rain, hazard maps, and safety behavior information of residents is generally conducted as a team by local government specialists who are responsible for administrative purposes. Private companies that provide information can also communicate disaster prevention information for specific areas.

The flowchart which showed the procedure from the prediction by the slope failure prediction of the present invention and the evacuation information transmission system to the surrounding area, analysis / evaluation, and information transmission. The curved surface figure which showed typically the collapse safety factor curved surface created from the inclination angle of each slope of monitoring object, the constant water level of this monitoring object slope, and the collapse safety factor. The basic information map which showed an example of the hazard map display in one Example to which this invention is applied. The hazard map which showed an example of the information display after the change at the time of rain in the basic information map shown in FIG. The example of a screen display which showed the example of a display of the safe action information with respect to the inhabitant obtained with the display of the hazard map shown in FIG.

Explanation of symbols

1 Collapse safety factor curved surface 2 Example of screen display of safe behavior information

Claims (4)

  A collapse safety factor curved surface database unit, an analysis unit that performs osmotic flow analysis on the basis of precipitation on each monitored slope obtained during rainfall to obtain a head change during rainfall, and the collapse safety factor curved surface database unit An evaluation unit that evaluates the collapsed safety factor of the monitored slope by comparing the safety factor curved surface stored in the head and the water head during rainfall, and the surrounding area based on the predicted situation of the monitored slope predicted from the evaluation result A slope failure prediction and evacuation information transmission system to the surrounding area, characterized by comprising a display transmission means for displaying and transmitting safety behavior information of residents.   The collapse safety factor curved surface is composed of a curved surface data group created from the relationship between the inclination angle of each slope to be monitored, the constant water level of the monitored slope, and the collapse safety factor, and is databased for each monitored slope. The slope failure prediction and evacuation information transmission system to the surrounding area according to claim 1 characterized by the above-mentioned.   The evaluation result is plotted on a digital numerical map provided in the display transmission means, and the evaluation result is updated on the digital numerical map according to a change with time of rainfall. The described slope failure prediction and evacuation information transmission system to the surrounding area.   The said display transmission means is a website on the Internet, a cable TV, or a wireless transmission device, and residents in the surrounding area can always access as the rainfall changes over time. Slope failure prediction and evacuation information transmission system to surrounding area.

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