CN115127754A - Aerial survey device and method for safety condition of earth-rock dam - Google Patents

Abstract

The invention discloses an earth and rockfill dam safety condition aerial inspection device and method, which comprises a smart inspection module, a smart monitoring module and a smart early warning module, wherein the smart inspection module comprises a plurality of panoramic earth and rockfill dam smart sensing elements, the smart monitoring module comprises a plurality of smart analysis elements, the smart early warning module comprises a plurality of smart early warning elements, and the smart inspection module is sequentially connected with the smart monitoring module and the smart early warning module. According to the local earth and rockfill dam safety condition aerial patrol detection device, three-dimensional intelligent sensing of earth and rockfill dam safety information can be achieved through the intelligent patrol detection module, earth and rockfill dam multi-source monitoring information is dug deeply and intelligently, comprehensive intelligent monitoring, reconstruction and learning are achieved, the safety situation of earth and rockfill dam engineering is predicted dynamically and accurately, and efficient intelligent management of the earth and rockfill dam engineering is achieved.

Description

Aerial survey device and method for safety condition of earth-rock dam

Technical Field

The invention relates to an earth and rockfill dam safety condition aerial patrol monitoring device and method, in particular to an integrated, universalized and intelligent earth and rockfill dam engineering safety monitoring device and method.

Background

Soil stone dykes and dams are at the in-service process, can often appear the crack, cave, diseases such as soft layer, can cause dykes and dams dorsal surface leakage phenomenon to appear, piping can appear even, soil flows, leakage hidden danger such as contact scouring, according to statistics, dam more than 90% has leakage phenomenon, wherein 30% has comparatively serious leakage hidden danger, its normal use that not only influences soil stone dykes and dams, can cause the incident that dam break and burst the dyke even, the spatial position and the distribution region of catching leakage hidden danger are extremely important to the safe operation of guarantee soil stone dykes and dams fast effectively.

The leakage of the earth and rockfill dam has the characteristics of complex reasons, uncertainty and concealment, the actual monitoring and patrolling difficulty of the leakage hidden danger of the earth and rockfill dam is very high, and the prior technical means comprise a manual inspection method, a geological drilling method, a direct current resistance method, a nuclear magnetic resonance method, a ground penetrating radar method, a seismic mapping method, a tracing method, a water balance method, a communication test method and the like; the manual exploration method and the geological drilling method are time-consuming and labor-consuming, poor in effect, and have the defects of blindness, high drilling cost, damage to the structure of the earth-rock dike dam and the like; the direct current resistance method belongs to a geophysical detection means, is an electrical detection technology and comprises a high-density resistivity method, a natural electric field method, a sequential electromagnetic method, an induced polarization method and the like, and the direct current resistance method and the nuclear magnetic resonance method are easily subjected to electromagnetic interference and have certain requirements on the form of leakage to be detected.

The unmanned aerial vehicle inspection leakage technology is rarely reported in the field, the current inspection is still carried out by means of manpower, at present, the discovery, identification and treatment of leakage dangerous cases are mainly based on the existing experience and conventional equipment, and the problems of large blind area, low efficiency, insufficient precision and the like exist by means of point monitoring, more and more novel technologies are introduced into the embankment safety monitoring field while the adaptability research of the detection of the leakage dangerous cases of earth and rockfill dams is carried out on the conventional monitoring technology, and the research of monitoring principles, implementation methods, technologies and the like of the novel technologies in embankment engineering is carried out, so that the research becomes a hot scientific research subject.

The air patrol dynamic intelligent sensing-monitoring-early warning system for the safety condition of the earth and rockfill dam is based on the defects of the conventional manual patrol at present, the data information acquisition and analysis are built in a front-end sensing module from the intelligent application, the strong heterogeneous data processing capacity is realized, the effective intelligent interconnection and intercommunication among data are realized, the comprehensiveness and comprehensiveness of the comprehensive analysis of the safety data information of dam engineering are realized through a multi-stage data storage and analysis module, the comprehensive judgment capacity is improved, and the time, the judgment efficiency and the precision of quick diagnosis are improved.

Disclosure of Invention

The purpose of the invention is as follows: the invention provides a novel complete device and a method applicable to embankment engineering safety monitoring, integrates a sensing-interpretation-analysis-early warning integrated novel front-end intelligent monitoring device, deeply excavates multi-source information of embankment engineering, realizes dynamic-full-time airspace internal monitoring, provides a feasible, effective and multifunctional intelligent monitoring system for large-volume embankment engineering safety integration, universalization and intelligent monitoring in a complex environment, and has outstanding advantages in the aspects of reducing monitoring cost, improving monitoring precision, improving engineering practicability and the like.

The technical scheme is as follows: the aerial survey device for the safety condition of the earth-rock dam comprises an intelligent survey module, an intelligent monitoring module and an intelligent early warning module; the intelligent patrol module comprises a plurality of intelligent sensing elements of the panoramic earth and rockfill dam, wherein the intelligent sensing elements of the panoramic earth and rockfill dam comprise 360-degree rotating magnetic disks, variable-pitch rods, lifting protective doors, adjusting rods, adjusting shafts, spraying pipes, emitters, photoelectric sensors, front diagonal tiger glasses heads, an image processor, a microcontroller, hot wire rings, a dripping grid net, a working cavity, an air floating cavity, rear diagonal tiger glasses heads, an arc pressing table and an elastic pushing body; the intelligent monitoring module comprises a plurality of intelligent analysis elements, and the intelligent early warning module comprises a plurality of intelligent early warning elements.

The aerial survey device of embankment dam safety situation, leading diagonal tiger glasses head is connected with 360 rotations magnetic discs, 360 rotation magnetic discs are connected with the regulation pole, it is connected with the accent axle to adjust the axle, it is connected with the displacement pole to adjust the axle, the working chamber is articulated with lift guard gate, the spray tube is connected with lift guard gate top, the hot wire circle is connected with lift guard gate inner edge, drip the net and be connected with lift guard gate lower edge, the displacement pole is connected with photoelectric sensor, photoelectric sensor is connected with image processor, image processor is connected with microcontroller.

Aerial survey device of going round of embankment dam safety situation, go up along setting up the spray tube on the lift guard gate, lay two parallel siphunculus in the spray tube, dispose high concentration in the parallel siphunculus and spout lotion and clear water, two parallel siphunculus spray each other with the time of once fifteen minutes at every interval, and use an hour as a cycle, the inboard inner edge of lift guard gate is provided with the hot wire circle, the hot wire circle is 360 encircles the setting, the hot wire circle can carry out the segmentation circular telegram, the hot wire circle has set up ten segmentation modes, be a circular telegram cycle every thirty minutes, lift guard gate lower edge disposes the graticule net, the lift guard gate position that the graticule net corresponds sets up the fluting, can spout timely sparse of lotion and clear water through the graticule net.

Aerial survey device of embankment dam safety situation, 360 rotate the disk right side and can carry out 360 rotations around adjusting the pole, set up multistage control pole in the regulation pole, can constantly go up and down coarse reconciliation fine setting as required.

Preferably, the adjusting shaft is a controllable angle control shaft, the angle of the adjusting shaft can be continuously adjusted according to needs to control the angle of the adjusting rod, the other end of the adjusting shaft is connected with the variable-pitch rod, and the variable-pitch rod can be changed in multiple stages to achieve multi-stage adjustment in the horizontal direction.

Preferably, limiting holes are formed in the adjusting shaft, the adjusting rod, the spraying pipe, the hot wire ring and the variable pitch rod, and the control cable is connected with the front diagonal tiger glasses head through the limiting holes.

Preferably, the front diagonal tiger glasses head is a uniquely-arranged wide-angle lens, a plurality of night vision micro lenses with different grades and a central large wide-angle lens are contained in the front diagonal tiger glasses head, the front diagonal tiger glasses head is similar to a 'tiger eye' form, and multi-lens mutual correction, all-weather wide-view angle and panoramic detection recording can be realized.

Preferably, the rear diagonal tiger glasses heads are symmetrically arranged with the front diagonal tiger glasses heads, and the area facing the rear diagonal tiger glasses heads is used for filling the area where the front diagonal tiger glasses heads cannot catch, and replacing and maintaining the rear diagonal tiger glasses heads when the front diagonal tiger glasses heads have problems.

Preferably, the air-bearing cavity is positioned at the top end of the intelligent sensing element of the panoramic earth-rock dam, and the front diagonal tiger glasses and the rear diagonal tiger glasses are always kept in the horizontal position under the condition that external wind power or the front and rear weight configuration of the self structure is uneven for the front and rear automatic balancing function.

Preferably, the arc structure of the arc pressing table can reduce wind resistance and improve air lifting force, energy consumption is reduced, duration of the arc pressing table is prolonged, the elastic pushing body is a flight system mounting structure, and the elastic pushing body can ensure that the aerial survey device for the safety condition of the earth-rock dam can be closely connected with the mounting body.

Preferably, the intelligent analysis element and the intelligent early warning element mainly receive external data information, and a multi-wavelet matrix decontamination program, a wavelet threshold decontamination program and a general empirical mode decomposition decontamination program are included to monitor and reflect the safety state of the earth-rockfill dam.

The operation method of the air survey device for the safety condition of the earth and rockfill dam comprises

The first step, be equipped with wisdom and patrol module, wisdom monitoring module, wisdom early warning module, connect panorama earth and rockfill dam wisdom sensing element.

And secondly, pulling the elastic pushing body, configuring the intelligent sensing element of the panoramic earth-rock dike dam on an unmanned aerial vehicle carrying platform, starting the air flotation cavity, starting the rear diagonal tiger glasses head, carrying out takeoff patrol environment inspection, keeping the lifting protective door in a closed state, starting the hot wire ring, and ensuring that the internal temperature and the cleaning state before the front diagonal tiger glasses head is opened are in good conditions.

And thirdly, starting all parts in the working cavity, starting a lifting protective door, adjusting the length of the adjusting rod, automatically moving out the front diagonal tiger glasses head, opening a 360-degree rotating magnetic disk, rotating the front diagonal tiger glasses head, opening a default 360-degree per minute automatic rotation mode, and automatically recording panoramic data information.

And fourthly, analyzing and monitoring the data information acquired by automatic patrolling in a smart monitoring module and a smart early warning module which gather the data information of the front diagonal tiger glasses head and the rear diagonal tiger glasses head acquired in real time, and evaluating the safety state of the patrolled earth and rock dam area.

And fifthly, after the patrol is finished, starting the variable pitch rod, withdrawing the front diagonal tiger glasses head, closing the lifting protective door, closing the hot wire ring, ensuring that the rear diagonal tiger glasses head is always in an open state, monitoring the flight attitude of the unmanned aerial vehicle and the safe landing area of the earth and rockfill dam in real time, and completing the safe patrol of the earth and rockfill dam.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages:

the intelligent monitoring system is high in efficiency, airspace and intelligent sensing of safety information of the earth and rock dam can be achieved through the intelligent patrol module, the intelligent monitoring module is fused after the intelligent monitoring system is used, multi-source information of operation conditions of the earth and rock dam is deeply and intelligently excavated, dynamic-full-time airspace monitoring is achieved, intelligent reconstruction and learning are conducted on different data information through the intelligent early warning module, the safety situation of earth and rock dam engineering is dynamically and accurately predicted, efficient intelligent management of the earth and rock dam engineering is achieved, and the intelligent monitoring system has excellent practical engineering application value and popularization potential.

Drawings

FIG. 1 is a block diagram of an aerial survey device for the safety of earth and rockfill dams

FIG. 2 is a three-dimensional structure diagram of a panoramic earth-rock dam intelligent sensing element

FIG. 3 is a detail view of the structure of diagonal tiger glasses head

FIG. 4 structural drawing of a drop grid

FIG. 5 shows an internal program diagram of the intelligent monitoring module and the intelligent pre-warning module

FIG. 6 a real scene of a dike project

Fig. 7 acquisition of leakage part of dike engineering

Wherein: 101-a dropping grid net, 102-a hot wire ring, 103-a lifting protective door, 104-a 360-degree rotating magnetic disc, 105-a spray pipe, 106-a front diagonal tiger glasses head, 107-an adjusting rod, 108-an adjusting shaft, 109-a variable-pitch rod, 110-a photoelectric sensor, 111-an image processor, 112-a microcontroller, 113-a rear diagonal tiger glasses head, 114-a working cavity, 115-an air floating cavity, 116-an arc pressing platform and 117-an elastic pushing body.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1, a block diagram of an aerial survey device for the safety condition of an earth-rock dam; as shown in FIG. 2, a front diagonal tiger glasses head 106 is connected with a 360-degree rotating magnetic disk 104 with the diameter of 8mm, the 360-degree rotating magnetic disk 104 with the diameter of 8mm is connected with a metal multistage adjusting rod 107, the metal multistage adjusting rod 107 is connected with a rectangular metal adjusting shaft 108, the rectangular metal adjusting shaft 108 is connected with a variable pitch rod 109 with the length of 80mm, a working chamber 114 with the radian of 120 degrees, the length of 400mm and the height of 100mm is hinged with a lifting guard door 103 with the length of 60mm and the width of 30mm, a built-in top spraying pipe 105 is connected with the top end of the lifting guard door 103 with the length of 60mm and the width of 30mm, a semicircular steel metal hot wire ring 102 is connected with the inner edge of the lifting guard door 103 with the length of 60mm and the width of 30mm, a dropping grid net 101(101) with the aperture of 2mm is connected with the lower edge of the lifting guard door 103 with the length of 60mm and the width of 30mm, the variable pitch rod 109 with the length of 80mm is connected with a photoelectric sensor 110, the photoelectric sensor 110 is connected with an image processor 111, the image processor 111 is connected to the microcontroller 112.

3 spraying pipes 105 are arranged on the upper edge of a lifting guard door 103 with the length of 60mm and the width of 30mm, two parallel through pipes are distributed in the spraying pipes 105, high-concentration spraying agent and clear water are configured in the parallel through pipes, the two parallel through pipes are sprayed at a time interval of fifteen minutes and circulate in a period of one hour, a semicircular steel metal hot wire ring 102 is arranged on the inner side of the lifting guard door 103, the semicircular steel metal hot wire ring 102 is arranged in a 360-degree surrounding manner, the semicircular steel metal hot wire ring 102 can be electrified in a segmented manner, ten segmented patterns are configured on the semicircular steel metal hot wire ring 102, an electrified period is set every thirty minutes, a grid 101(101) with the aperture of 2mm is configured on the lower edge of the lifting guard door 103 as shown in figure 4, a groove is formed in the position of the lifting guard door 103 corresponding to the grid 101(101) with the aperture of 2mm, and spraying agent and clear water can be timely evacuated through the grid 101(101) with the aperture of 2mm, the right side of the 360-degree rotating magnetic disc 104 can rotate 360 degrees around the metal multi-stage adjusting rod 107, and a multi-stage control rod is arranged in the metal multi-stage adjusting rod 107 and can be lifted, coarsely adjusted and finely adjusted continuously as required.

The rectangular metal adjusting shaft 108 is a controllable angle control shaft, the angle of the rectangular metal adjusting shaft can be continuously adjusted according to needs to control the angle of the metal multistage adjusting rod 107, the other end of the adjusting shaft 108 is connected with the variable pitch rod 109, the variable pitch rod 109 can be changed in multiple stages to achieve horizontal multistage adjustment, the rectangular metal adjusting shaft 108, the metal multistage adjusting rod 107, the spray pipe 105, the semicircular steel metal hot wire ring 102 and the variable pitch rod 109 are internally provided with limit holes, a control cable is connected with the front diagonal tiger eye lens 106 through the limit holes, as shown in fig. 3, the diagonal tiger eye lens is a uniquely-arranged wide-angle lens and internally provided with a plurality of night vision micro lenses in different levels and a central large wide-angle lens, and is similar to a tiger eye form, and multi-lens mutual correction, all-weather wide-view angle and panoramic detection recording can be achieved.

The rear diagonal tiger glasses heads 113 and the front diagonal tiger glasses heads 106 are symmetrically arranged, the areas facing the rear diagonal tiger glasses heads 113 are used for filling the areas where the front diagonal tiger glasses heads 106 cannot capture, and the rear diagonal tiger glasses heads 113 are used for replacement, maintenance and use when the front diagonal tiger glasses heads 106 have problems.

The air flotation cavity 115 is located at the top end of the intelligent sensing element of the panoramic earth and rockfill dam, and has a front and back automatic balancing function, the front diagonal tiger glasses and the rear diagonal tiger glasses head 113 are always in a horizontal position under the condition that external wind power or the front and back weight configuration of the self structure is uneven, the arc pressing table 116 arc structure with the radian of 120 degrees can reduce wind resistance and improve air lifting force, energy consumption is reduced, the duration of the self structure is prolonged, the elastic pushing body 117 with the maximum stretching length of 300m is a flight system mounting structure, and the elastic pushing body 117 can ensure that the aerial patrol detection device of the safety condition of the earth and rockfill dam can be closely connected with a carrying body.

A certain dike project is selected, an actual project diagram is shown in figure 6, patrol analysis within a range of 2km is carried out, automatic patrol information acquisition is carried out through the front diagonal tiger glasses and the rear diagonal tiger glasses heads 113, information reflecting the safety of the dike project is automatically acquired based on the intelligent analysis element and the intelligent early warning element, and a dike leakage area is found through internal programs of the intelligent monitoring module and the intelligent early warning module shown in figure 5, and is required to be observed in time to prevent further expansion and influence on the safety of the dike project.

Various changes in form and detail may be made therein without departing from the principles of the invention and such changes and modifications are to be considered as within the scope of the invention.

Claims (10)

1. The utility model provides an aerial survey device of earth and rockfill dam safe condition which characterized in that: the intelligent monitoring system comprises an intelligent patrol module, an intelligent monitoring module and an intelligent early warning module; the intelligent patrol module comprises a plurality of intelligent sensor elements of the panoramic earth and rockfill dam, wherein the intelligent sensor elements of the panoramic earth and rockfill dam comprise 360-degree rotating magnetic disks (104), a variable pitch rod (109), a lifting protective door (103), an adjusting rod (107), an adjusting shaft (108), a spraying pipe (105), a transmitter, a photoelectric sensor (110), a front diagonal tiger glasses head (106), an image processor (111), a microcontroller (112), a hot wire ring (102), a dripping grid net (101), a working chamber (114), an air floating chamber (115), a rear diagonal tiger glasses head (113), an arc pressing table (116) and an elastic pushing body (117); the intelligent monitoring module comprises a plurality of intelligent analysis elements, and the intelligent early warning module comprises a plurality of intelligent early warning elements.

2. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: the front diagonal tiger glasses head (106) is connected with a 360-degree rotating magnetic disk (104), the 360-degree rotating magnetic disk (104) is connected with an adjusting rod (107), the adjusting rod (107) is connected with an adjusting shaft (108), the adjusting shaft (108) is connected with a variable-pitch rod (109), a working cavity (114) is hinged with a lifting guard gate (103), a spraying pipe (105) is connected with the top end of the lifting guard gate (103), a hot wire ring (102) is connected with the inner edge of the lifting guard gate (103), a dropping grid net (101) is connected with the lower edge of the lifting guard gate (103), the variable-pitch rod (109) is connected with a photoelectric sensor (110), the photoelectric sensor (110) is connected with an image processor (111), and the image processor (111) is connected with a microcontroller (112).

3. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: the upper edge of the lifting protective door (103) is provided with a spraying pipe (105), two parallel through pipes are distributed in the spraying pipe (105), high-concentration spraying agent and clear water are arranged in the parallel through pipes, the two parallel through pipes are sprayed with each other at a time interval of fifteen minutes and circulate in a cycle of one hour, a hot wire ring (102) is arranged on the inner edge of the inner side of the lifting protective door (103), the hot wire ring (102) is arranged in a 360-degree surrounding manner, the hot wire ring (102) can be electrified in a segmented manner, the hot wire ring (102) is provided with ten segmented modes, an electrified cycle is carried out every thirty minutes, the lower edge of the lifting protective door (103) is provided with a grid dripping net (101), a groove is arranged at the position of the lifting protective door (103) corresponding to the grid dripping net (101), the spraying agent and the clear water can be timely evacuated through the grid dripping net (101), the right side of a 360-degree rotating magnetic disc (104) can rotate by 360 degrees around the adjusting rod (107), set up multistage control pole in adjusting pole (107), can constantly carry out lift coarse adjustment and fine setting as required, transfer axle (108) are a controllable type angle control axle, can constantly adjust its angle as required and control regulation pole (107) angle, and the other end and the displacement pole (109) of transfer axle (108) are connected, and the multistage adjustment that the level was to can the multistage change realization of displacement pole (109).

4. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: limiting holes are formed in the adjusting shaft (108), the adjusting rod (107), the spraying pipe (105), the hot wire ring (102) and the variable-pitch rod (109), and the control cable is connected with the front diagonal tiger glasses head (106) through the limiting holes.

5. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: the front diagonal tiger glasses head (106) is a uniquely arranged wide-angle lens and comprises a plurality of night vision micro lenses with different grades and a central large wide-angle lens.

6. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: the rear diagonal tiger glasses head (113) and the front diagonal tiger eye lens (106) are symmetrically arranged, the area facing the rear diagonal tiger glasses head (113) is used for filling the area where the front diagonal tiger glasses head (106) cannot catch, and the rear diagonal tiger glasses head (113) is used for replacement, maintenance and use when the front diagonal tiger glasses head (106) has problems.

7. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: the air floating cavity (115) is positioned at the top end of the intelligent sensing element of the panoramic earth and rockfill dam, and the front diagonal tiger glasses and the rear diagonal tiger glasses head (113) are always in a horizontal position under the condition that external wind power or the front and rear weight of the self structure are not uniformly configured for the front and rear automatic balancing function.

8. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: arc pressure platform (116) arc structure can reduce the windage and promote air lifting strength, reduces the consumption of energy and improves self duration, and elasticity propelling movement body (117) are flight system carry structure, and elasticity propelling movement body (117) can guarantee that the aerial survey device of embankment dam safety situation can closely contact with the carrier.

9. The aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein: the intelligent analysis element and the intelligent early warning element mainly receive external data information, and a multi-wavelet matrix decontamination program, a wavelet threshold decontamination program and a general empirical mode decomposition decontamination program are included to monitor and reflect the safety state of the earth-rockfill dam.

10. The operation method of the aerial survey device for the safety condition of the earth and rockfill dam according to claim 1, wherein:

firstly, an intelligent patrol module, an intelligent monitoring module and an intelligent early warning module are arranged and connected with an intelligent sensing element of the panoramic earth-rockfill dam;

secondly, pulling the elastic pushing body (117), configuring the intelligent sensing element of the panoramic earth-rock dike dam on an unmanned aerial vehicle carrier, starting the air floating cavity (115), starting the rear diagonal tiger glasses head (113), carrying out takeoff patrol environment inspection, starting the hot wire ring (102) under the condition that the lifting protective door (103) is kept closed, and ensuring that the internal temperature and the cleaning state are in good conditions before the front diagonal tiger glasses head (106) is opened;

thirdly, starting all parts in the working cavity (114), starting the lifting protective door (103), adjusting the length of the adjusting rod (107), automatically moving out the front diagonal tiger glasses head (106), starting the 360-degree rotating magnetic disk (104), rotating the front diagonal tiger glasses head (106), starting a default 360-degree automatic rotation mode per minute, and automatically recording panoramic data information;

fourthly, analyzing and monitoring the data information obtained by automatic patrol in a smart monitoring module and a smart early warning module which gather the data information of the front diagonal tiger glasses head (106) and the rear diagonal tiger glasses head (113) obtained in real time, and evaluating the safety state of the patrolled earth and stone dam area;

and fifthly, after the patrol is finished, starting a variable pitch rod (109), withdrawing the front diagonal tiger glasses head (106) from the front diagonal tiger glasses head, closing a lifting protective door (103), closing a hot wire ring (102), ensuring that the rear diagonal tiger glasses head (113) is always in an open state, monitoring the flight attitude of the unmanned aerial vehicle and the safe landing area of the earth and rockfill dam in real time, and finishing the safe patrol of the earth and rockfill dam.

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