CN210368913U

CN210368913U - Collapsible loess area test system that soaks

Info

Publication number: CN210368913U
Application number: CN201920845159.1U
Authority: CN
Inventors: 刘魁; 李国庆; 杨博文; 范文燕; 张�浩
Original assignee: China Electronic Research Institute Of Engineering Investigations And Design; Changan University
Current assignee: China Electronic Research Institute Of Engineering Investigations And Design; Changan University
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2020-04-21
Anticipated expiration: 2029-06-05

Abstract

The utility model discloses a collapsible loess area immersion test system, which comprises an upper monitoring terminal, a soil deformation monitoring device and a vertical loading device, wherein the soil deformation monitoring device comprises a data collector and M combined detection devices which are uniformly distributed along the circumferential direction; each combined detection device comprises N detection pieces distributed from bottom to top, the N detection pieces positioned on the same water surface in the filling layer to be tested form a transverse detection device, the vertical surface of each combined detection device is a soil monitoring surface, and the filling layer to be tested is divided into M soil detection areas through the M soil monitoring surfaces. The utility model relates to a rationally, the test is simple and convenient and excellent in use effect, adopts a plurality of combination formula detection device to wait to examine the soil body deformation of soil packing layer in to the foundation ditch and detect comprehensively, combination formula detection device position reasonable in design just buries underground portably, can carry out portably, quick and accurate test to the collapsibility of loess soil packing layer comprehensively.

Description

Collapsible loess area test system that soaks

Technical Field

The utility model belongs to the technical field of geotechnical engineering detects and tests, especially, relate to a collapsible loess area test system that soaks.

Background

From the viewpoint of on-site construction, the foundation is classified into a natural foundation and an artificial foundation. The foundation is a bearing rock-soil bearing layer under the foundation. The natural foundation can meet the requirement of bearing all loads of the foundation in a natural state, a natural soil layer reinforced by people is not needed, the engineering cost is saved, and the foundation does not need manual treatment. The natural foundation is a natural soil layer which can be directly laid without treating the foundation. Artificial foundations are foundations that have been artificially treated or modified. When the geological condition of the soil layer is better and the bearing capacity is stronger, a natural foundation can be adopted; under the condition of poor geological conditions, such as sloping fields, sandy fields or silt geology, or when the texture of the soil layer is good but the upper load is too large, in order to ensure that the foundation has enough bearing capacity, the foundation is artificially reinforced, namely the artificial foundation. Among the artificial foundations, a foundation formed by backfilling the foundation with filling soil (also referred to as backfill soil) is referred to as a filled foundation, a backfill soil foundation, a filled foundation, and the like. Collapsible loess is widely distributed in China and accounts for about 60 percent of the total area of the loess area. In the re-collapsible loess area, a filling foundation of collapsible loess (also referred to as a loess fill) is used more frequently.

At present, the main purpose of foundation treatment is to adopt various foundation treatment methods to improve the foundation conditions. The objects of the foundation treatment are soft foundation and special soil foundation. The special soil foundation has regional characteristics and comprises foundations such as soft soil, collapsible loess, expansive soil, red clay, frozen soil and the like. The collapsible property of the collapsible loess foundation can bring different degrees of harm to the structure, so that the structure is greatly settled, cracked and inclined, and even the safety and the use of the structure are seriously influenced. Therefore, when building structures such as bridges and culverts in loess areas, reliable judgment method and comprehensive knowledge are provided for collapsible loess foundation, and correct engineering measures are taken to prevent or eliminate the collapsible property of the collapsible loess foundation, and the process is called collapsible loess foundation treatment. Before the collapsible loess foundation is treated, a pit test and water immersion test needs to be carried out on the collapsible loess foundation to be treated so as to determine the collapsible property of the collapsible loess foundation. However, at present, when a loess fill layer is subjected to a water immersion test, no standard test method can be followed, and problems of random construction operation, numerous adopted detection elements, random detection element embedding positions, large embedding workload, unreliable test results and the like inevitably exist in the actual test. Therefore, at present, a loess fill layer immersion test device which is reasonable in design, simple and convenient in test and good in using effect is lacking, the collapsibility of the loess fill layer can be simply, conveniently, quickly and accurately tested, so that the collapsibility of the loess fill layer can be comprehensively known, and comprehensive and reliable basis is provided for later-stage foundation treatment.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem lie in not enough to among the above-mentioned prior art, a collapsible loess area test system that soaks is provided, its structural design is reasonable, the test is simple and convenient and excellent in use effect, adopt a plurality of combination formula detection device that evenly lay along the circumferencial direction to await measuring the soil body deformation of soil filling layer in the foundation ditch and detect comprehensively, combination formula detection device position reasonable in design just buries portably underground, and through combination formula detection device with the foundation ditch in await measuring the soil filling layer divide into a plurality of soil body detection areas, every soil body detection area all carries out soil body deformation through a combination formula detection device and detects, can carry out the collapsible nature of loess filling layer comprehensively portably, quick and accurate test.

In order to solve the technical problem, the utility model discloses a technical scheme is: the utility model provides a collapsible loess area test system that soaks which characterized in that: the device comprises an upper monitoring terminal, a soil body deformation monitoring device and a vertical loading device for vertically loading a to-be-tested fill layer from top to bottom, wherein the vertical loading device is positioned right above the to-be-tested fill layer; the soil deformation monitoring device comprises a data collector and M combined detection devices uniformly distributed in the soil filling layer to be tested along the circumferential direction, and the M combined detection devices have the same structure; wherein M is a positive integer and M is not less than 3; the data acquisition unit is connected with an upper monitoring terminal;

the filling layer to be tested is formed by filling loess into foundation pits formed by excavation in advance in a layered mode and tamping the loess, and the foundation pits are foundation layers filled with the loess from top to bottom; the water immersion test pit is a cylindrical vertical foundation pit, the diameter of the water immersion test pit is phi 1.8 m-phi 2.5m, the fill layer to be tested is a cylindrical soil layer, the height h1 of the fill layer to be tested is 2.5 m-4 m, wherein h1 is less than h2, and h2 is the depth of the water immersion test pit;

each combined detection device comprises N detection pieces distributed on the same vertical surface from bottom to top, and the position of each detection piece is a soil monitoring point; wherein N is a positive integer and N is not less than 5; each detection piece comprises a soil moisture sensor for detecting the moisture content of the soil body at the position in real time, a soil tensiometer for detecting the soil water suction force at the position in real time and a displacement sensor for detecting the vertical displacement value at the position in real time, the soil moisture sensor, the soil tensiometer and the displacement sensor in each detection piece are uniformly distributed on the same soil body monitoring point, and the soil moisture sensor, the soil tensiometer and the displacement sensor are all connected with a data acquisition unit;

n detection pieces positioned on the same water surface in the filling layer to be tested form a transverse detection device, and the filling layer to be tested is provided with N transverse detection devices from bottom to top;

the vertical surface where all detection pieces are located in each combined detection device is a soil body monitoring surface, the filling layer to be tested is divided into M soil body detection areas through M soil body monitoring surfaces, the structures of the M soil body detection areas are the same, and the cross section of each soil body detection area is in a fan shape.

Above-mentioned collapsible loess area test system that soaks, characterized by: the upper monitoring terminal is a smart phone or a notebook computer.

Above-mentioned collapsible loess area test system that soaks, characterized by: the soil moisture sensor, the soil tensiometer and the displacement sensor are connected with the data collector through connecting wires;

each combined detection device further comprises a vertical sleeve which is embedded outside a filling layer to be detected and is used for the connecting line to pass through and a plurality of threading pipes which are used for the connecting line to pass through, the threading pipes are arranged from bottom to top, the number of the threading pipes is the same as that of the detection pieces in each combined detection device, and the upper end of each vertical sleeve extends out of the water immersion test pit; the outer end of each threading pipe is connected to the vertical sleeve, N connecting holes for connecting the threading pipes are formed in the inner side wall of the vertical sleeve from bottom to top, and each threading pipe is communicated with the inside of the vertical sleeve connected with the threading pipe; the soil moisture sensor, the soil tensiometer and the displacement sensor are all positioned at the inner end of the threading pipe;

every be connected with soil moisture sensor, soil tensiometer and displacement sensor in the detection piece the connecting wire all penetrates vertical sleeve pipe intraductally, every through same root threading pipe all wear out same vertical sleeve pipe from all connecting wires that are connected with soil moisture sensor, soil tensiometer and displacement sensor among the combination formula detection device.

Above-mentioned collapsible loess area test system that soaks, characterized by: every the detection piece all still includes a waterproof camera that whether there is the crack to the position department that locates to detect, waterproof camera is connected with data collection station.

Above-mentioned collapsible loess area test system that soaks, characterized by: the waterproof camera is connected with the data collector through the connecting wire and is positioned at the inner end of the threading pipe; it is same all connecting wires that are connected with soil moisture sensor, soil tensiometer, displacement sensor and waterproof camera among the detection piece all penetrate vertical cover intraductally through same root threading pipe.

Above-mentioned collapsible loess area test system that soaks, characterized by: at least one detection part in each combined detection device comprises a temperature sensor for detecting the soil temperature at the position in real time, and the temperature sensor is connected with a data acquisition unit.

Above-mentioned collapsible loess area test system that soaks, characterized by: the filling soil layer to be tested is divided into a lower soil layer and an upper soil layer positioned below the lower soil layer, and the lower soil layer and the upper soil layer are the same in height;

the number of the detection pieces positioned in the lower soil layer in each combined detection device is not less than two, the distance between two adjacent detection pieces above and below the lower soil layer is d1, and d1 is 0.45-0.55 m; the distance between two adjacent detection pieces in the upper soil layer is d2, and d2 is 0.2-0.3 m; the distance between the uppermost detecting element in the lower soil layer and the top surface of the lower soil layer is not more than d1, and the distance between the lowermost detecting element in the lower soil layer and the bottom surface of the lower soil layer is not more than d 1; the distance between the uppermost detection element in the upper soil layer and the top surface of the upper soil layer is not more than d2, and the distance between the lowermost detection element in the upper soil layer and the bottom surface of the upper soil layer is not more than d 2.

Above-mentioned collapsible loess area test system that soaks, characterized by: and a sand and gravel filling layer is paved on the filling layer to be tested.

Above-mentioned collapsible loess area test system that soaks, characterized by: the vertical loading device comprises a pressurizing plate which is flatly paved on the sandy gravel filling layer, a jack which is arranged right above the pressurizing plate, a horizontal distribution beam which is supported on the jack and a stacking object which is arranged on the horizontal distribution beam.

Compared with the prior art, the utility model has the following advantage:

1. reasonable structural design, simple and convenient processing and manufacture and lower input cost.

2. Easy to embed and easy to use and operate.

3. The combined detection device has the advantages that the use effect is good, the practical value is high, the combined detection devices which are uniformly distributed along the circumferential direction are adopted to comprehensively detect the soil deformation of the filling layer to be detected in the foundation pit, the combined detection device is reasonable in position design and simple and convenient to embed, the filling layer to be detected in the foundation pit is divided into a plurality of soil detection areas through the combined detection device, each soil detection area is subjected to soil deformation detection through one combined detection device, the collapsibility of the loess filling layer can be comprehensively tested simply, conveniently, quickly and accurately, the test result is reliable, and accurate, comprehensive and reliable bases can be provided for the later construction of the loess filling layer. The test result of the collapsibility of the loess filling layer is the immersion test result of the filling layer to be tested, the immersion test result is the soil deformation condition of the filling layer to be tested, the relation between the soil deformation condition and the soil moisture content change condition and the soil water suction change condition and the maximum load borne by the filling layer to be tested after immersion, and meanwhile, whether cracks exist in the filling layer to be tested can be monitored in time.

The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

Fig. 1 is a reference diagram of the usage state of the present invention.

Fig. 2 is a schematic diagram of the layout position of the combined detecting device of the present invention.

Fig. 3 is a schematic structural view of the combined detecting device of the present invention.

Fig. 4 is a schematic block diagram of the circuit of the present invention.

Fig. 5 is a flow chart of a method for performing a water immersion test according to the present invention.

Description of reference numerals:

1-a fill to be tested; 2, an upper monitoring terminal; 3, foundation pit;

4-soil moisture sensor; 5-a displacement sensor; 6-temperature sensor;

7-data collector; 8, vertical sleeve; 9-a threading pipe;

10-waterproof camera; 11-sand and pebble filling layer; 12-a compression plate;

13-a jack; 14-horizontal distribution beam; 15-stacking;

16-a loading force detection unit; 17-a vertical support; 18-a soil tensiometer;

19-mounting a groove; 20-a separator; 21-inner end detecting piece;

22-loess filling foundation; 23-combined detection device.

Detailed Description

As shown in fig. 1, fig. 2, fig. 3 and fig. 4, the utility model comprises an upper monitoring terminal 2, a soil deformation monitoring device and a vertical loading device for vertically loading a filling layer 1 to be tested from top to bottom, wherein the vertical loading device is positioned right above the filling layer 1 to be tested; the soil deformation monitoring device comprises a data acquisition unit 7 and M combined detection devices 23 uniformly distributed in the fill layer 1 to be tested along the circumferential direction, and the structures of the M combined detection devices 23 are the same; wherein M is a positive integer and M is not less than 3; the data acquisition unit 7 is connected with the upper monitoring terminal 2;

the filling layer 1 to be tested is a filling layer formed by filling loess into a foundation pit 3 formed by excavation in advance and tamping the loess, the foundation pit 3 is a soaking test pit formed by excavation in a loess filling foundation 22 from top to bottom, and the loess filling foundation 22 is a loess filling layer formed by backfilling the loess; the water immersion test pit is a cylindrical vertical foundation pit, the diameter of the water immersion test pit is phi 1.8 m-phi 2.5m, the soil filling layer 1 to be tested is a cylindrical soil layer, the height h1 of the soil filling layer is 2.5 m-4 m, h1 is less than h2, and h2 is the depth of the water immersion test pit;

each combined detection device 23 comprises N detection pieces distributed on the same vertical surface from bottom to top, and the position of each detection piece is a soil monitoring point; wherein N is a positive integer and N is not less than 5; each detection piece comprises a soil moisture sensor 4 for detecting the moisture content of the soil body at the position in real time, a soil tensiometer 18 for detecting the soil water suction at the position in real time and a displacement sensor 5 for detecting the vertical displacement value at the position in real time, the soil moisture sensor 4, the soil tensiometer 18 and the displacement sensor 5 in each detection piece are uniformly distributed on the same soil body monitoring point, and the soil moisture sensor 4, the soil tensiometer 18 and the displacement sensor 5 are all connected with a data collector 7;

n detection pieces positioned on the same water surface in the filling layer 1 to be tested form a transverse detection device, and the N transverse detection devices are arranged in the filling layer 1 to be tested from bottom to top;

the vertical surface of all the detection pieces in each combined detection device 23 is a soil monitoring surface, the filling layer 1 to be tested is divided into M soil detection areas through M soil monitoring surfaces, the structures of the M soil detection areas are the same, and the cross section of each soil detection area is in a fan shape.

The M combined detection devices 23 have the same structure and size. Moreover, all the detecting elements in the M combined detecting devices 23 form N transverse detecting devices, and each transverse detecting device includes M detecting elements arranged on the same horizontal plane.

Because the soil moisture sensor 4, the soil tensiometer 18 and the displacement sensor 5 in each detection piece are all positioned on the same soil body monitoring point, according to the data detected by the soil moisture sensor 4, the soil tensiometer 18 and the displacement sensor 5, not only can the soil body deformation data (namely the vertical displacement data detected by the displacement sensor 5) of the soil body monitoring point be obtained, but also the relation between the change situation of the settlement value (namely the vertical displacement detected by the displacement sensor 5) of the soil body monitoring point and the change situation of the soil moisture content (namely the soil moisture detected by the soil moisture sensor 4) of the soil body monitoring point and the soil water suction force (namely the soil water suction force detected by the soil tensiometer 18) of the soil body monitoring point can be directly obtained.

The N detection pieces in each combined detection device 23 are arranged on the same soil monitoring surface, so that according to data detected by the N detection pieces in each combined detection device 23, not only can soil deformation data (namely, vertical displacement data detected by the N displacement sensors 5) on the soil monitoring surface be obtained, but also the relationship between the change situation of the sedimentation value on the soil monitoring surface and the change situation of the soil moisture content on the soil monitoring surface and the change situation of the soil water suction on the soil monitoring surface can be simply, rapidly, comprehensively, visually and accurately obtained. The soil deformation data on the soil monitoring surface is consistent with the soil deformation condition of the soil detection area where the soil monitoring surface is located, the soil moisture content change condition on the soil monitoring surface is consistent with the soil moisture content change condition of the soil detection area where the soil monitoring surface is located, and the soil water suction change condition on the soil monitoring surface is consistent with the soil water suction change condition of the soil detection area where the soil monitoring surface is located. Therefore, the soil deformation condition of the soil detection area where the soil monitoring surface is located can be correspondingly obtained, and meanwhile, the relation between the soil deformation condition of the soil detection area where the soil monitoring surface is located and the change condition of the soil moisture content and the change condition of the soil water suction force can be obtained.

In addition, as the N transverse detection devices are arranged in the filling layer 1 to be tested from bottom to top, according to the data detected by the M detection pieces in each transverse detection device, not only can the soil deformation data (namely the vertical displacement data detected by the M displacement sensors 5) on the transverse monitoring surface be obtained, but also the relationship between the change situation of the sedimentation value on the transverse monitoring surface and the change situation of the soil moisture content and the soil water suction force can be simply, rapidly, comprehensively, intuitively and accurately obtained.

According to the above content, the soil deformation condition of the filling layer 1 to be tested can be simply, conveniently, quickly, visually, comprehensively and accurately detected through the water immersion test device, and the relation between the soil deformation condition of the filling layer 1 to be tested and the change condition of the soil moisture content and the change condition of the soil water suction force can be obtained, so that the collapsibility of the filling layer 1 to be tested can be quickly, comprehensively and accurately known.

The distance between the soil monitoring surface and the central axis of the foundation pit is 0.4-0.7 m.

In this embodiment, the distance between the soil monitoring surface and the central axis of the foundation pit is 0.5 m. During actual construction, the distance between the soil monitoring surface and the central axis of the foundation pit can be correspondingly adjusted according to specific requirements.

In actual construction, M is 2, 3, 4, 5 or 6.

In this embodiment, M is 2.

During actual use, the value of M can be correspondingly adjusted according to the diameter of the foundation pit and specific detection requirements.

In this embodiment, N is 7.

During actual construction, the value of N can be correspondingly adjusted according to the size of h1 and specific detection requirements.

In this embodiment, the upper monitoring terminal 2 is a smart phone or a notebook computer.

In practical use, the upper monitoring terminal 2 may also adopt other types of controllers or upper computers, and only needs to be able to detect the upper monitoring requirement.

For reliable monitoring, the soil moisture sensor 4, the soil tensiometer 18, the displacement sensor 5 and the data acquisition unit 7 are connected through connecting wires.

In this embodiment, each of the combined detection devices 23 further includes a vertical sleeve 8 embedded outside the filling layer 1 to be tested and allowing the connection line to pass through, and a plurality of threading pipes 9 allowing the connection line to pass through, the plurality of threading pipes 9 are arranged from bottom to top, the number of the threading pipes 9 is the same as the number of the detection pieces included in each of the combined detection devices 23, and the upper end of the vertical sleeve 8 extends out of the water-immersion test pit; the outer end of each threading pipe 9 is connected to the vertical sleeve 8, N connecting holes for connecting the threading pipes 9 are formed in the inner side wall of the vertical sleeve 8 from bottom to top, and each threading pipe 9 is communicated with the inside of the vertical sleeve 8 connected with the threading pipe 9; the soil moisture sensor 4, the soil tensiometer 18 and the displacement sensor 5 are all positioned at the inner end of the threading pipe 9;

every be connected with soil moisture sensor 4, soil tensiometer 18 and displacement sensor 5 in the detection piece the connecting wire all penetrates vertical sleeve pipe 8 in through same root threading pipe 9, every all connecting wires that are connected with soil moisture sensor 4, soil tensiometer 18 and displacement sensor 5 in the combination formula detection device 23 all wear out from same root vertical sleeve pipe 8.

In this embodiment, the outer end of each threading tube 9 is hermetically connected with the vertical sleeve 8 connected with the threading tube.

When actually burying, M vertical sleeves 8 are uniformly arranged along the circumferential direction.

In order to ensure the waterproof effect, the vertical sleeve 8 and the threading pipe 9 are waterproof pipes.

In this embodiment, the vertical casing 8 is a hard plastic pipe, and the threading pipe 9 is a hose. Therefore, the practical threading is very simple and convenient, the processing is simple and convenient, and the using effect is good.

In order to ensure the accuracy of data detection, all the threading pipes 9 in each combined detection device 23 are uniformly distributed on the same vertical surface.

For satisfying the detection demand to the crack in the fill layer 1 that awaits measuring, every the detection piece all still includes a waterproof camera 10 that detects whether there is the crack to the position department of locating, waterproof camera 10 is connected with data collection station 7.

In this embodiment, the waterproof camera 10 is connected with the data collector 7 through the connecting line, and the waterproof camera 10 is located at the inner end of the threading pipe 9; it is same all connecting wires that are connected with soil moisture sensor 4, soil tensiometer 18, displacement sensor 5 and waterproof camera 10 in the detection piece all penetrate through in the vertical sleeve pipe 8 through same root threading pipe 9. Thus, the actual wiring is very simple.

Meanwhile, at least one of the detection parts in each of the combined detection devices 23 includes a temperature sensor 6 for detecting the soil temperature at the position in real time, and the temperature sensor 6 is connected with the data collector 7.

In this embodiment, the temperature sensor 6 is connected with the data collector 7 through the connecting line, and the temperature sensor 6 is located at the inner end of the threading pipe 9; it is same all connecting wires connected with soil moisture sensor 4, soil tensiometer 18, displacement sensor 5, waterproof camera 10 and temperature sensor 6 in the detection piece all penetrate through in the vertical sleeve pipe 8 through same root threading pipe 9.

In this embodiment, the threading tube 9 is horizontally disposed.

It can be known by the above-mentioned content, it is same that combination formula detection device 23 only adopts a vertical sleeve pipe 8, and is same all detecting element in the detection piece (including soil moisture sensor 4, soil tensiometer 18, displacement sensor 5, waterproof camera 10 and temperature sensor 6) all adopts same root threading pipe 9, and all connecting wires all carry out rationally like this, effectively gather, and on-the-spot threading, wiring and line change are all very simple and convenient to be convenient for carry out data acquisition in the later stage, made things convenient for on-the-spot line management in the very big degree, reduced constructor work load. Meanwhile, the combined detection device 23 is convenient to embed in site, all connecting wires penetrate through the threading pipe 9 and the vertical sleeve 8, the structure of the combined detection device (23) is greatly simplified, only the threading pipe 9 and the vertical sleeve 8 are required to be embedded, and the embedding difficulty and the embedding workload of a large number of detection elements are greatly reduced; meanwhile, the accuracy of the burying position of each detection element (namely the soil monitoring point) can be ensured. And, all connecting wires all wear to locate in threading pipe 9 and vertical sleeve 8, can effectively carry out water repellent to can ensure detection effect, ensure each detecting element's waterproof performance and detection effect, and can effectively improve each detecting element's life. In addition, the combined detection device 23 is very simple and convenient to take out and disassemble from the soil body, can be repeatedly used for multiple times, and can effectively improve the turnover efficiency of the combined detection device 23 and accelerate turnover times, so that the construction cost is further saved.

In this embodiment, each of the detecting members is an inner end detecting member 21 located at the inner end of the threading pipe 9.

In this embodiment, M installation grooves 19 for installing the combined type detection device 23 are formed in the circumferential side of the to-be-tested fill layer 1 from top to bottom, and the installation grooves 19 are vertical grooves formed by digging in the soil body on the circumferential side of the to-be-tested fill layer 1 from top to bottom.

During actual construction, the mounting groove 19 is a groove formed by manual excavation, and the mounting groove 19 is also called a probe groove.

In order to ensure that the mounting grooves 19 cannot influence the filling layer 1 to be tested, a partition plate 20 is arranged in each mounting groove 19, the partition plate 20 is vertically arranged and is abutted against the outer side wall of the filling layer 1 to be tested, and the filling layer 1 to be tested is separated from the inside of the mounting groove 19 through the partition plate 20. In this embodiment, the partition board 20 is a wood board. And, N through holes for the threading pipes 9 to pass through are arranged on the partition plate 20 from top to bottom.

In this embodiment, a gravel and sand filling layer 11 is laid on the filling layer 1 to be tested.

The filling layer to be tested 1 is divided into a lower soil layer and an upper soil layer positioned below the lower soil layer, and the lower soil layer and the upper soil layer have the same height;

the number of the detection pieces positioned in the lower soil layer in each combined detection device 23 is not less than two, the distance between two adjacent detection pieces above and below the lower soil layer is d1, and d1 is 0.45-0.55 m; the distance between two adjacent detection pieces in the upper soil layer is d2, and d2 is 0.35-0.45 m; the distance between the uppermost detecting element in the lower soil layer and the top surface of the lower soil layer is not more than d1, and the distance between the lowermost detecting element in the lower soil layer and the bottom surface of the lower soil layer is not more than d 1; the distance between the uppermost detection element in the upper soil layer and the top surface of the upper soil layer is not more than d2, and the distance between the lowermost detection element in the upper soil layer and the bottom surface of the upper soil layer is not more than d 2.

In this embodiment, the diameter of the foundation pit (also referred to as a test pit) is 2m and the depth thereof is 3.3 m.

D1 is 0.5m, d2 is 0.4 m.

During actual construction, the diameter and the depth of the foundation pit and the values of d1 and d2 can be adjusted correspondingly according to specific requirements.

In this embodiment, the height h1 of the filling layer 1 to be tested is 3m, the height of the upper soil layer and the height of the lower soil layer are both 1.5m, and the thickness of the sand and gravel filling layer 11 is 0.1 m. And the vertical distance between the top surface of the sand and gravel filling layer 11 and the top surface of the top pit is 0.2 m. During actual construction, the height h1 of the filling layer 1 to be tested, the thickness of the sand and gravel filling layer 11 and the vertical distance between the top surface of the sand and gravel filling layer 11 and the top surface of the pit can be correspondingly adjusted according to specific requirements.

In this embodiment, the distance between the lowermost detecting element in the lower soil layer and the bottom surface of the lower soil layer is 0.1m, the distance between the uppermost detecting element in the lower soil layer and the top surface of the lower soil layer is 0.2m, and the distance between the lowermost detecting element in the upper soil layer and the bottom surface of the upper soil layer is 0.2m, so that the distance between the uppermost detecting element in the lower soil layer and the lowermost detecting element in the upper soil layer is 0.4 m.

During actual construction, the distance between two adjacent upper and lower detection pieces in the combined detection device 23 can be adjusted correspondingly according to specific requirements.

In this embodiment, the vertical loading device includes a pressure plate 12 laid on the gravel packing layer 11, a jack 13 arranged right above the pressure plate 12, a horizontal distribution beam 14 supported on the jack 13, and a ballast 15 arranged on the horizontal distribution beam 14.

And simultaneously, the utility model discloses still include the loading power detecting element 16 that carries out real-time detection to the vertical loading power on the increased pressure board 12, loading power detecting element 16 is connected with upper monitor terminal 2. The loading force value detected by the loading force detection unit 16 is used for determining the load borne by the filling layer 1 to be tested, so that the aim of detecting the actual load borne by the filling layer 1 to be tested in real time is fulfilled.

In this embodiment, the pressing plate 12 is a horizontal steel plate, and the pressing plate 12 is a circular steel plate with a diameter smaller than that of the water-soaking test pit.

The vertical loading device further comprises two vertical supporting members 17 supported below two ends of the horizontal distribution beam 14, and the vertical supporting members 17 are supported on the pressurizing plate 12.

During actual construction, firstly excavating a foundation pit from top to bottom on a loess foundation to form the foundation pit, and treating the bottom of the foundation pit, specifically, tamping the bottom of the foundation pit by using a tamper (a small-sized tamper is adopted here), so that the bottom of the foundation pit is compacted loess (namely collapsible loess) with the thickness of 3m, and the compaction coefficient is 0.85-0.90; adopt collapsible loess right again the foundation ditch is backfilled, adopts the rammer (here adopts small-size rammer) to tamp the backfill soil and the compaction coefficient of backfill soil (the compaction coefficient of the fill layer 1 that awaits measuring promptly) is 0.85 ~ 0.90, obtains the fashioned fill layer 1 that awaits measuring of construction.

In this embodiment, before backfilling the foundation pit, an installation trench 19 needs to be excavated around the foundation pit, and the foundation pit is separated from the installation trench 19 by a partition plate 20. And finally, backfilling the foundation pit by adopting collapsible loess, tamping the backfilled soil by adopting a small-sized tamping machine in the backfilling process, and ensuring the compactness of each part of the filled soil layer 1 to be tested due to the arrangement of the partition plates 20.

Because the combined detection device 23 is high in height, the combined detection device is inconvenient to actually install and high in installation difficulty, the installation process of the combined detection device 23 can be simply, conveniently and quickly completed through the installation groove 19, and the construction process is safe and reliable.

And after the construction of the filling layer 1 to be tested is finished, burying a plurality of combined detection devices 23 respectively. When any one of the combined detection devices 23 is buried, a plurality of horizontal mounting holes for mounting the threading pipes 9 and the detection pieces are chiseled on the side wall of the filling layer 1 to be tested, the mounted combined detection device 23 is placed in the mounting groove 19, the threading pipes 9 with the detection pieces at the inner ends are respectively mounted in the horizontal mounting holes, and the mounting process of the combined detection device 23 is completed. By adopting the mounting method, the accuracy of the embedding position of each detection piece can be effectively ensured, and the influence of the tamping process on the embedding position of each detection piece is reduced or even avoided. And after the plurality of combined detection devices 23 are buried, obtaining the soil deformation monitoring device.

During actual construction, after the plurality of combined detection devices 23 are buried, the mounting grooves 19 can be backfilled respectively, the adopted backfill soil is the same as that adopted by the filling layer 1 to be tested, the backfill soil backfilling the mounting grooves 19 is tamped, and the compaction coefficient is the same as that of the filling layer 1 to be tested.

In this embodiment, the side wall of the installation groove 19 close to one side of the to-be-tested fill layer 1 is vertically arranged, and the side wall of the installation groove 19 far away from one side of the to-be-tested fill layer 1 is step-shaped, so that the installation groove 19 is easy and convenient to excavate, the excavated and formed installation groove 19 is stable in structure, and the width of the upper part of the installation groove 19 is greater than the width of the bottom of the installation groove.

As shown in FIG. 5, the utility model discloses when adopting the experiment of soaking, including following step:

step one, burying a soil layer backfill and combined type detection device 23: backfilling loess into the pre-excavated and molded water-soaked test pit, and compacting the filled loess through compaction equipment until the compaction coefficient of the filled loess meets the design requirement to obtain a backfilled to-be-tested fill layer 1; meanwhile, M combined detection devices 23 are embedded in the filling layer 1 to be tested to obtain the soil deformation monitoring device;

step two, monitoring the deformation of the soil body before soaking: monitoring the filling layer 1 to be tested for multiple times by adopting the soil deformation monitoring device in the first step from first to last, and judging whether the filling layer 1 to be tested is in a soil deformation stable state or not according to a monitoring result; the soil deformation monitoring device has the same method for monitoring the filling layer 1 to be tested for multiple times, and the monitoring time interval between two adjacent times is t1, wherein t1 is 10-20 min;

when the soil deformation monitoring device in the first step is adopted to monitor the filling layer 1 to be tested, the process is as follows:

step 201, monitoring soil deformation for the first time before soaking: after the backfill layer 1 to be tested is backfilled in the first step, monitoring the backfill layer 1 to be tested by adopting the soil deformation monitoring device to obtain soil deformation data of the backfill layer 1 to be tested at the moment, and synchronously uploading the soil deformation data of the backfill layer 1 to be tested at the moment to an upper monitoring terminal 2 and synchronously recording the data;

the soil deformation data comprises soil moisture content values detected by all soil moisture sensors 4, soil water suction values detected by all soil tensiometers 18 and displacement values detected by all displacement sensors 5 in the soil deformation monitoring device; at this time, the displacement value detected by each displacement sensor 5 is the initial displacement value of the displacement sensor 5;

step 202, monitoring soil deformation for the next time before soaking: monitoring the filling layer 1 to be tested by adopting the soil deformation monitoring device to obtain soil deformation data of the filling layer 1 to be tested at the moment, and synchronously uploading the soil deformation data of the filling layer 1 to be tested at the moment to an upper monitoring terminal 2 and synchronously recording the data; meanwhile, obtaining the accumulated settlement amount of each displacement sensor 5 in the soil deformation monitoring device at the moment according to the initial displacement value of each displacement sensor 5 in the step 201; the accumulated settlement amount of each displacement sensor 5 is the difference between the displacement value detected by the displacement sensor 5 at the moment and the initial displacement value of the displacement sensor 5;

step 203, soil deformation stability judgment: comparing the soil deformation data obtained in the step 202 with previous deformation data, and when a difference value between a displacement value detected by each displacement sensor 5 in the soil deformation data obtained in the step 202 and a displacement value detected by the displacement sensor 5 in the previous deformation data is not greater than 0.5mm, indicating that the filling layer 1 to be tested is in a soil deformation stable state at the moment, and entering a step 204; otherwise, returning to the step 202, and monitoring the next soil deformation before soaking;

the last deformation data is the soil deformation data obtained when the filling layer 1 to be tested is monitored last time; the soil deformation data obtained in step 202 is present deformation data, and the previous deformation data is soil deformation data obtained by monitoring the to-be-tested fill layer 1 with the soil deformation monitoring device at the previous time, so that the detection time interval between the previous deformation data and the present deformation data is t 1;

step 204, soil body crack rough judgment: according to the accumulated settlement of each displacement sensor 5 in the soil deformation monitoring device at the moment, roughly judging whether cracks exist in the filling layer 1 to be tested at the moment: when the difference value between the accumulated settlement amounts of two adjacent displacement sensors 5 in each transverse detection device of the soil deformation monitoring device is smaller than 3mm, indicating that no crack exists in the filling layer 1 to be tested, and entering the fourth step; otherwise, entering the third step;

step three, continuously backfilling the soil layer: continuously backfilling loess on the filling layer 1 to be tested, and compacting the filled loess through a compaction device to obtain the filling layer 1 to be tested after continuous backfilling; then, entering the step two;

step four, soaking: injecting water into the filling layer 1 to be tested by using water injection equipment until the water immersion process of the filling layer 1 to be tested is completed;

step five, loading: the vertical loading device is adopted to load the filling layer 1 to be tested in a multi-stage mode from first to last, after each stage of loading, the soil deformation monitoring device is adopted to monitor the soil deformation of the filling layer 1 to be tested, and the adopted monitoring methods are the same;

when the vertical loading device is used for carrying out any one-stage loading on the filling layer 1 to be tested, the soil deformation monitoring device in the step one is used for monitoring the filling layer 1 to be tested for multiple times from first to last; the soil deformation monitoring device has the same method for monitoring the filling layer 1 to be tested for multiple times, and the monitoring time interval of two adjacent times is t2, wherein t2 is 25-35 min;

when the vertical loading device is adopted to carry out any level loading on the filling layer 1 to be tested, the process is as follows:

step 501, loading: loading the to-be-tested fill layer 1 by adopting the vertical loading device;

step 502, monitoring the deformation of the loaded soil body for the first time: monitoring the filling layer 1 to be tested by adopting the soil deformation monitoring device to obtain soil deformation data of the filling layer 1 to be tested at the moment, and simultaneously uploading the soil deformation data of the filling layer 1 to be tested at the moment to an upper monitoring terminal 2 and synchronously recording the data;

step 503, monitoring the deformation of the soil body for the next time after loading: monitoring the filling layer 1 to be tested by adopting the soil deformation monitoring device to obtain soil deformation data of the filling layer 1 to be tested at the moment, and synchronously uploading the soil deformation data of the filling layer 1 to be tested at the moment to an upper monitoring terminal 2 and synchronously recording the data; meanwhile, obtaining the accumulated settlement amount of each displacement sensor 5 in the soil deformation monitoring device at the moment according to the initial displacement value of each displacement sensor 5 in the step 201; the accumulated settlement amount of each displacement sensor 5 is the difference between the displacement value detected by the displacement sensor 5 at the moment and the initial displacement value of the displacement sensor 5;

the last deformation data is the soil deformation data obtained when the filling layer 1 to be tested is monitored last time;

step 504, soil stability rough judgment: and judging whether the filling layer 1 to be tested is stable according to the accumulated settlement of each displacement sensor 5 in the soil deformation monitoring device at the moment: when the difference value between the accumulated settlement amounts of two adjacent displacement sensors 5 in each transverse detection device of the soil deformation monitoring device is smaller than 3mm, indicating that the filling layer 1 to be tested is in a stable state at the moment, and entering step 505; otherwise, the filling layer 1 to be tested is in a destabilization state at the moment, and the water immersion test process of the filling layer 1 to be tested is completed;

step 505, judgment of completion of loading: judging whether the whole loading process of the filling layer 1 to be tested is finished at the moment, and finishing the immersion test process of the filling layer 1 to be tested when the whole loading process of the filling layer 1 to be tested is finished at the moment; otherwise, go to step 506;

step 506, next-stage loading: and (4) carrying out next-stage loading on the filling layer 1 to be tested according to the method from the step 501 to the step 504.

After the loading is finished in the fifth step, a soaking test result is obtained; the immersion test result comprises soil deformation data obtained when the soil deformation monitoring device monitors the filling layer 1 to be tested each time.

In step 504, when the difference value between the accumulated settlement amounts of two adjacent displacement sensors 5 in each transverse detection device of the soil deformation monitoring device is smaller than 3mm, it is determined that the filled soil layer 1 to be tested can bear the load loaded on the filled soil layer 1 to be tested in step 501 after being soaked; otherwise, the filled soil layer 1 to be tested cannot bear the load loaded on the filled soil layer 1 to be tested in the step 501 after the water is soaked. Therefore, adopt the utility model discloses can be direct, accurate reach the load at different levels that the back examination of awaiting measuring filled soil layer 1 can bear after soaking to can directly obtain the biggest load that the back examination of awaiting measuring filled soil layer 1 can bear after soaking.

In this embodiment, t1 in step two is 15min, and t2 in step five is 30 min. In actual tests, the values of t1 and t2 can be adjusted correspondingly according to specific needs.

According to the above content, the deformation condition of the soil body of the filling layer 1 to be tested before and after soaking can be simply, conveniently, quickly, comprehensively and accurately monitored by adopting the utility model; meanwhile, before immersion, soil deformation monitoring is carried out on the filling layer 1 to be tested for many times from first to last, after soil deformation monitoring is carried out each time, whether the filling layer 1 to be tested is stable or not is judged simply, conveniently, quickly and accurately according to the detection result of the soil deformation monitoring device (specifically, the accumulated settlement amount of each displacement sensor 5 in the soil deformation monitoring device), and whether the filling layer 1 to be tested reaches the soil stable state after immersion or not is judged according to the soil stability rough judgment result: only when the filling layer 1 to be tested is judged to be in a stable state at the moment, the step 204 is carried out to roughly judge the soil body crack, and the main reason is that only when the filling layer 1 to be tested is in a stable state at the moment, the filling layer 1 to be tested is in a stable state before soaking, the filling layer 1 to be tested before soaking can be soaked and loaded, the soaking and loading are effective at the moment, the soaking load test result is effective, and the reference value is realized; otherwise, when the filling layer 1 to be tested is in an unstable state at this moment, the filling layer 1 to be tested does not need to be soaked and loaded, the filling layer 1 to be tested cannot bear the loading at all, the soaking load test result is invalid, and the manpower and material resource investment can be effectively reduced.

The soil deformation stability judgment method adopted in the step 203 has reasonable design, convenient realization and accurate judgment result, and can simply, conveniently and quickly judge whether the filling layer 1 to be tested is in a stable state before soaking.

In addition, when the filling layer 1 to be tested is in a stable state after the soil deformation stability judgment in the step 203, the step 204 needs to be entered for soil crack rough judgment, and when the filling layer 1 to be tested is in a stable state before soaking and no crack exists in the filling layer 1 to be tested, the filling layer 1 to be tested is in a real stable state at this moment; otherwise, when the soil deformation stability judgment in the step 203 indicates that the filling layer 1 to be tested is in a stable state, but the soil crack rough judgment in the step 204 indicates that a crack exists in the filling layer 1 to be tested at this time, the filling layer 1 to be tested is only in a temporary stable state at this time, the existing crack is continuously developed, so that the filling layer 1 to be tested is inevitably in an unstable state again, then the filling layer 1 to be tested can be soaked and loaded, the soaking load test is effective at this time, and the obtained test result can have a reference value; otherwise, when the soil crack rough judgment in the step 204 shows that a crack exists in the filling layer 1 to be tested at the moment, the filling layer 1 to be tested still needs to be refilled until no crack exists in the filling layer 1 to be tested, so that the soaking load test (namely the soaking test) of the unstable filling layer can be avoided, the manpower and material resource investment is reduced, meanwhile, the soaking load test result of the unstable filling layer also has no reference value, and the bearing capacity and the settlement result of the unstable filling layer also cannot meet the actual bearing demand, the unstable filling layer cannot be practically applied, and no utilization value or reference value exists. The compaction coefficient (also called compaction degree) of the filling layer 1 to be tested is further adjusted through continuous backfilling, and the compaction coefficient when the filling layer 1 to be tested is in a stable state can be correspondingly obtained, so that an accurate and reliable basis is provided for the compaction coefficient in the subsequent application process of the filling layer 1 to be tested, when the loess filling foundation 22 with the same soil quality as that of the filling layer 1 to be tested is backfilled in the later period, the compaction coefficient is the same as the obtained compaction coefficient when the filling layer 1 to be tested is in the stable state, the stability of the loess filling foundation 22 can be guaranteed, and the practical application value is very high. In this embodiment, the foundation pit and the filling layer 1 to be tested are both located in the loess fill foundation 22.

In this embodiment, the loess fill foundation 22 is a collapsible loess foundation.

Correspondingly, foundation ditch 3 is for digging the soaking test pit that forms in loess fill ground 22 from top to bottom, the test fill layer 1 that awaits measuring is through filling the filling layer that collapsible loess and tamp the back formation in the layering into foundation ditch 3 that forms to excavation in advance to the collapsible loess that fills in is the same with the collapsible loess that loess fill ground 22 adopted.

The soil body crack rough judgment method adopted in the step 204 is novel and reasonable in design, convenient to implement and accurate in judgment result, and can simply, conveniently and quickly judge whether the filling layer 1 to be tested has cracks or not.

In addition, adopt vertical loading device is by earlier to after divide the multistage to the examination fill layer 1 that awaits measuring to carry out the loading in-process, after each level loading, adopts the utility model discloses can go on portably, quick, comprehensive and accurate monitoring to the examination fill layer 1's that awaits measuring soil body deformation condition before soaking and after soaking.

After each level of loading, according to the detection result of the soil deformation monitoring device (specifically, the accumulated settlement amount of each displacement sensor 5 in the soil deformation monitoring device), whether the to-be-tested fill layer 1 is stable at this time can be simply, quickly and accurately judged, and whether the next level of loading is needed is judged according to the soil stability rough judgment result: only when the filling layer 1 to be tested is in a stable state at this time, the next-stage loading is carried out in the step 506, and the main reason is that only when the filling layer 1 to be tested is in a stable state after the loading of the current stage, the filling layer 1 to be tested can bear the loading of the current stage, and the next-stage loading is necessary; otherwise, the next-stage loading is not needed, the manpower and material resource investment can be effectively reduced, and the immersion test result has reference value.

The soil stability rough judgment method adopted in the step 504 is reasonable in design, convenient to implement and accurate in judgment result, and can simply, conveniently and quickly judge whether the filling layer 1 to be tested is in a stable state after the loading of the current level.

And step five, when the vertical loading device is adopted to load the filling layer 1 to be tested in a multi-stage mode from front to back, the recording force is gradually increased from front to back. In step 501, when the vertical loading device is used for loading the filling layer 1 to be tested, the loaded load is 15 kPa-25 kPa, wherein the loaded load is a surface load acting on the filling layer 1 to be tested by using the vertical loading device, namely, a vertical acting force in a unit area (namely, each square meter). When the next stage of loading is carried out in the step 506, the load loaded this time is 15 kPa-25 kPa greater than the load loaded by the previous stage.

In this embodiment, when the vertical loading device is used to load the filling layer 1 to be tested in step 501, the loaded load is 20 kPa; when the next stage of loading is performed in step 506, the load loaded this time is 20kPa greater than the load loaded by the previous stage.

In this embodiment, in order to facilitate loading and avoid damage to the to-be-tested fill layer 1 in the vertical loading process, in the step one, after the to-be-tested fill layer 1 is backfilled, a layer of sandy gravel filling layer 11 needs to be laid on the to-be-tested fill layer 1.

In this embodiment, after the rough judgment of the soil cracks is completed in step 204, the existence area of the soil cracks needs to be judged;

when the soil crack existing region is judged, M soil detection regions are respectively judged; the judging methods of the M soil body detection areas are the same;

when any soil detection area is judged, judging according to the accumulated settlement amount of two displacement sensors 5 positioned at two sides of the soil detection area in the N transverse detection devices of the soil deformation monitoring device in step 204: when the difference value between the accumulated settlement amounts of the two displacement sensors 5 positioned at the two sides of the soil detection area in each transverse detection device is smaller than 3mm, judging that no crack exists in the soil detection area; otherwise, judging that the soil body detection area is a soil body crack existence area;

and when the soil layer is continuously backfilled in the third step, the loess is continuously backfilled above the soil crack existence area judged at the moment, and the filled loess is compacted through the compaction equipment.

After judging soil body crack existence region, can be direct, simple and convenient, quick and accurate find out soil body crack existence region, when carrying out the soil layer in the step three and continue to backfill, only need right soil body crack existence region continue to backfill loess and tamp can, therefore can simply and conveniently, quick and accurate find out unstable region and carry out backfill processing, effectively practice thrift manpower and materials and drop into, and save the time limit for a project, can effectively change the unstable state of examination fill layer 1 that awaits measuring simultaneously, practical value is high.

In this embodiment, each of the detecting members further includes a waterproof camera 10 for detecting whether a crack exists at the position where the detecting member is located, and the waterproof camera 10 is connected to the data collector 7;

after the soil crack rough judgment is completed in step 204, video acquisition is performed by using each waterproof camera 10 in the soil deformation monitoring device, and the acquired video information is synchronously transmitted to the upper monitoring terminal 2.

During the in-service use, the video information that each waterproof camera 10 gathered is shown through upper monitor terminal 2, just can be simple and convenient, fast and directly perceived the crack condition of each soil body monitoring point week side and accurately know.

When the flooding is carried out in the fourth step, when the water head height of the filling layer 1 to be tested is h0, completing the flooding process of the filling layer 1 to be tested; wherein h0 is the height from the upper surface of the filling layer 1 to be tested to the water surface of the water reserved above the filling layer 1 to be tested, and h0 is 20-30 cm;

and in the loading process in the fifth step, the water head height of the filling layer 1 to be tested is h 0.

In this example, h0 is 20 cm.

During actual construction, the value of h0 can be adjusted according to specific needs.

In this embodiment, when the immersion is performed in the fourth step, the process is as follows:

step 401, soaking: injecting water into the filling layer 1 to be tested by adopting water injection equipment, and entering step 402 when the water head height of the filling layer 1 to be tested is h 0;

step 402, monitoring soil deformation for the first time after soaking: after the backfill layer 1 to be tested is backfilled in the first step, monitoring the backfill layer 1 to be tested by adopting the soil deformation monitoring device to obtain soil deformation data of the backfill layer 1 to be tested at the moment, and synchronously uploading the soil deformation data of the backfill layer 1 to be tested at the moment to an upper monitoring terminal 2 and synchronously recording the data;

step 403, monitoring soil deformation for the next time after soaking: monitoring the filling layer 1 to be tested by adopting the soil deformation monitoring device to obtain soil deformation data of the filling layer 1 to be tested at the moment, and synchronously uploading the soil deformation data of the filling layer 1 to be tested at the moment to an upper monitoring terminal 2 and synchronously recording the data; meanwhile, obtaining the accumulated settlement amount of each displacement sensor 5 in the soil deformation monitoring device at the moment according to the initial displacement value of each displacement sensor 5 in the step 201; the accumulated settlement amount of each displacement sensor 5 is the difference between the displacement value detected by the displacement sensor 5 at the moment and the initial displacement value of the displacement sensor 5;

step 404, soil deformation stability judgment: comparing the soil deformation data obtained in the step 403 with previous deformation data, and when a difference between a displacement value detected by each displacement sensor 5 in the soil deformation data obtained in the step 403 and a displacement value detected by the displacement sensor 5 in the previous deformation data is not greater than 0.5mm, indicating that the filling layer 1 to be tested is in a soil deformation stable state at this time, and entering a step 405; otherwise, returning to the step 403, and monitoring the next soil deformation after soaking;

step 405, soil body crack rough judgment: according to the accumulated settlement of each displacement sensor 5 in the soil deformation monitoring device at the moment, roughly judging whether cracks exist in the filling layer 1 to be tested at the moment: when the difference value between the accumulated settlement amounts of two adjacent displacement sensors 5 in each transverse detection device of the soil deformation monitoring device is smaller than 3mm, indicating that no crack exists in the filling layer 1 to be tested, and entering a fifth step; otherwise, go to step 406;

step 406, continuously backfilling soil layers: continuously backfilling loess on the filling layer 1 to be tested, and compacting the filled loess through a compaction device to obtain the filling layer 1 to be tested after continuous backfilling; and then, injecting water into the filling layer 1 to be tested by using a water injection device, and entering the step 402 when the water head height of the filling layer 1 to be tested is h 0.

After the step four is soaked and before loading, the vertical loading device is adopted, and the soil deformation condition of the soil filling layer 1 to be tested in the soaking process can be simply, conveniently, quickly, comprehensively and accurately monitored in multiple times from front to back. Besides the first soil deformation monitoring after the soaking, after each soil deformation monitoring, whether the filling layer 1 to be tested is stable or not is judged simply, conveniently, quickly and accurately according to the detection result of the soil deformation monitoring device (specifically, the accumulated settlement amount of each displacement sensor 5 in the soil deformation monitoring device) and whether the filling layer 1 to be tested reaches the soil stable state after the soaking or not is judged according to the soil stability rough judgment result: only when the filling layer 1 to be tested is judged to be in a stable state at the moment, entering step 405 to perform soil body crack rough judgment, wherein the main reason is that only when the filling layer 1 to be tested is in the stable state at the moment, the filling layer 1 to be tested is in the stable state after being soaked, the filling layer 1 to be tested after being soaked can bear loading, the loading is effective at the moment, the soaking load test result is effective, and the reference value is realized; otherwise, when the filling layer 1 to be tested is in an unstable state at this time, loading is not needed, the filling layer 1 to be tested cannot bear the loading at all, and the immersion load test result is invalid, so that the manpower and material resource investment can be effectively reduced.

The soil deformation stability judgment method adopted in the step 404 is reasonable in design, convenient to implement and accurate in judgment result, and can simply, conveniently and quickly judge whether the filling layer 1 to be tested is in a stable state after the loading of the current level.

In addition, when the filling layer 1 to be tested is in a stable state after the soil deformation stability judgment in the step 404, the step 405 is required to perform soil crack rough judgment, and when the filling layer 1 to be tested is in a stable state after being soaked in water and no crack exists in the filling layer 1 to be tested, the filling layer 1 to be tested is in a real stable state at this time; otherwise, when the soil deformation stability judgment in the step 404 indicates that the filling layer 1 to be tested is in a stable state, but the soil crack rough judgment in the step 405 indicates that the filling layer 1 to be tested is only in a temporary stable state at the moment, the existing cracks are continuously developed to inevitably cause the filling layer 1 to be tested to be in an unstable state again, then the filling layer 1 to be tested can be loaded, the water immersion load test is effective at the moment, and the obtained test result can have a reference value; otherwise, when the soil crack rough judgment in the step 405 shows that a crack exists in the filling layer 1 to be tested at the moment, the filling layer 1 to be tested still needs to be refilled until the soil crack rough judgment shows that no crack exists in the filling layer 1 to be tested, so that the soaking load test (namely the soaking test) on the unstable filling layer can be avoided, the manpower and material resource investment is reduced, meanwhile, the soaking load test result of the unstable filling layer also has no reference value, and the bearing capacity and the settlement result of the unstable filling layer also cannot meet the actual bearing requirement, the unstable filling layer cannot be practically applied, and no utilization value or reference value exists. The compaction coefficient (also called compaction degree) of the filling layer 1 to be tested is further adjusted through continuous backfilling, and the compaction coefficient when the filling layer 1 to be tested is in a stable state can be correspondingly obtained, so that an accurate and reliable basis is provided for the compaction coefficient in the subsequent application process of the filling layer 1 to be tested, when the loess filling foundation 22 with the same soil quality as that of the filling layer 1 to be tested is backfilled in the later period, the compaction coefficient is the same as the obtained compaction coefficient when the filling layer 1 to be tested is in the stable state, the stability of the loess filling foundation 22 can be guaranteed, and the practical application value is very high.

The soil body crack rough judgment method adopted in the step 405 has novel and reasonable design, convenient realization and accurate judgment result, and can simply, conveniently and quickly judge whether the filling layer 1 to be tested has cracks.

In this embodiment, when the immersion is performed in the fourth step, the process is as follows: after the soil body crack rough judgment is completed in the step 405, judging the existence area of the soil body crack;

when any soil detection area is judged, judging according to the accumulated settlement amount of two displacement sensors 5 positioned at two sides of the soil detection area in the N transverse detection devices of the soil deformation monitoring device in the step 405: when the difference value between the accumulated settlement amounts of the two displacement sensors 5 positioned at the two sides of the soil detection area in each transverse detection device is smaller than 3mm, judging that no crack exists in the soil detection area; otherwise, judging that the soil body detection area is a soil body crack existence area;

and in the step 406, when the soil layer is continuously backfilled, continuously backfilling loess above the judged soil crack existence area, and compacting the filled loess through a compaction device.

After judging the soil crack existence region, the soil crack existence region can be directly, simply, quickly and accurately found out, when the soil layer is continuously backfilled in the step 406, only the soil crack existence region needs to be continuously backfilled with loess and tamped, so that the unstable region can be simply, quickly and accurately found out and backfilled, the manpower and material resource investment is effectively saved, the construction period is shortened, the unstable state of the soil filling layer 1 to be tested can be effectively changed, and the practical value is high.

In this embodiment, after the soil crack rough judgment is completed in step 405, each waterproof camera 10 in the soil deformation monitoring device needs to be used to perform video acquisition, and the acquired video information is synchronously transmitted to the upper monitoring terminal 2.

During actual construction, the vertical distance between the upper surface of the sand and gravel filling layer 11 and the upper surface of the water-soaking test pit is not less than h 0.

In this embodiment, the vertical distance between the upper surface of the sand and gravel packing layer 11 and the upper surface of the water-soaking test pit is h 0.

The above, only be the utility model discloses a preferred embodiment, it is not right the utility model discloses do any restriction, all according to the utility model discloses the technical entity all still belongs to any simple modification, change and the equivalent structure change of doing above embodiment the utility model discloses technical scheme's within the scope of protection.

Claims

1. The utility model provides a collapsible loess area test system that soaks which characterized in that: the device comprises an upper monitoring terminal (2), a soil body deformation monitoring device and a vertical loading device for vertically loading a to-be-tested fill layer (1) from top to bottom, wherein the vertical loading device is positioned right above the to-be-tested fill layer (1); the soil deformation monitoring device comprises a data collector (7) and M combined detection devices (23) which are uniformly distributed in the fill layer (1) to be tested along the circumferential direction, wherein the M combined detection devices (23) have the same structure; wherein M is a positive integer and M is not less than 3; the data acquisition unit (7) is connected with the upper monitoring terminal (2);

the filling layer (1) to be tested is a filling layer formed by filling loess into a foundation pit (3) formed by excavation in advance and tamping the loess, the foundation pit (3) is a soaking test pit formed by excavation in a loess filling foundation (22) from top to bottom, and the loess filling foundation (22) is a loess filling layer formed by backfilling the loess; the water immersion test pit is a cylindrical vertical foundation pit, the diameter of the water immersion test pit is phi 1.8 m-phi 2.5m, the soil filling layer (1) to be tested is a cylindrical soil layer, the height h1 of the soil filling layer is 2.5 m-4 m, h1 is less than h2, and h2 is the depth of the water immersion test pit;

each combined detection device (23) comprises N detection pieces distributed on the same vertical surface from bottom to top, and the position of each detection piece is a soil monitoring point; wherein N is a positive integer and N is not less than 5; each detection piece comprises a soil moisture sensor (4) for detecting the moisture content of the soil body at the position in real time, a soil tensiometer (18) for detecting the soil moisture suction at the position in real time and a displacement sensor (5) for detecting the vertical displacement value at the position in real time, the soil moisture sensor (4), the soil tensiometer (18) and the displacement sensor (5) in each detection piece are uniformly distributed on the same soil body monitoring point, and the soil moisture sensor (4), the soil tensiometer (18) and the displacement sensor (5) are all connected with a data acquisition unit (7);

n detection pieces positioned on the same water surface in the filling layer (1) to be tested form a transverse detection device, and N transverse detection devices are arranged in the filling layer (1) to be tested from bottom to top;

the vertical surface where all detection pieces are located in each combined detection device (23) is a soil body monitoring surface, the soil filling layer (1) to be tested is divided into M soil body detection areas through M soil body monitoring surfaces, the structures of the M soil body detection areas are the same, and the cross section of each soil body detection area is in a fan shape.

2. The collapsible loess area submergence test system according to claim 1, wherein: the upper monitoring terminal (2) is an intelligent mobile phone or a notebook computer.

3. The collapsible loess area submergence test system according to claim 1 or 2, wherein: the soil moisture sensor (4), the soil tensiometer (18), the displacement sensor (5) and the data collector (7) are connected through connecting wires;

each combined detection device (23) further comprises a vertical sleeve (8) which is embedded outside the filling layer (1) to be tested and through which the connecting line passes and a plurality of threading pipes (9) through which the connecting line passes, the threading pipes (9) are arranged from bottom to top, the number of the threading pipes (9) is the same as that of the detection pieces included in each combined detection device (23), and the upper end of the vertical sleeve (8) extends out of the water immersion test pit; the outer end of each threading pipe (9) is connected to the vertical sleeve (8), N connecting holes for connecting the threading pipes (9) are formed in the inner side wall of the vertical sleeve (8) from bottom to top, and each threading pipe (9) is communicated with the inside of the vertical sleeve (8) connected with the threading pipe (9); the soil moisture sensor (4), the soil tensiometer (18) and the displacement sensor (5) are all positioned at the inner end of the threading pipe (9);

every be connected with soil moisture sensor (4), soil tensiometer (18) and displacement sensor (5) in the detection piece the connecting wire all penetrates vertical sleeve pipe (8) through same root threading pipe (9), every all connecting wires that are connected with soil moisture sensor (4), soil tensiometer (18) and displacement sensor (5) in combination formula detection device (23) all wear out from same root vertical sleeve pipe (8).

4. The collapsible loess area submergence test system according to claim 3, wherein: every the detection piece all still includes one and whether there is the waterproof camera (10) that the crack detected to the position department of locating, waterproof camera (10) are connected with data collection station (7).

5. The collapsible loess area submergence test system according to claim 4, wherein: the waterproof camera (10) is connected with the data collector (7) through the connecting line, and the waterproof camera (10) is positioned at the inner end of the threading pipe (9); it is same detect all connecting wires that are connected with soil moisture sensor (4), soil tensiometer (18), displacement sensor (5) and waterproof camera (10) in the piece and all penetrate in vertical sleeve pipe (8) through same root threading pipe (9).

6. The collapsible loess area submergence test system according to claim 1 or 2, wherein: at least one detection piece in each combined detection device (23) comprises a temperature sensor (6) for detecting the soil temperature at the position in real time, and the temperature sensor (6) is connected with a data acquisition unit (7).

7. The collapsible loess area submergence test system according to claim 1 or 2, wherein: the filling layer (1) to be tested is divided into a lower soil layer and an upper soil layer positioned below the lower soil layer, and the lower soil layer and the upper soil layer are the same in height;

8. The collapsible loess area submergence test system according to claim 1 or 2, wherein: a layer of sand-gravel filling layer (11) is paved on the filling soil layer (1) to be tested.

9. The collapsible loess area submergence test system according to claim 8, wherein: the vertical loading device comprises a pressurizing plate (12) paved on the sand and gravel filling layer (11), a jack (13) arranged right above the pressurizing plate (12), a horizontal distribution beam (14) supported on the jack (13) and a stacking object (15) arranged on the horizontal distribution beam (14).