A reservoir immersion test simulation system and method

Abstract

The embodiment of the present application provides a reservoir immersion test simulation system and method, which relates to the field of geological engineering reservoir immersion research. The system includes a constant pressure water supply subsystem, a water storage chamber, a test soil box, and a capillary soil column. The water storage chamber is used to simulate the reservoir water level before and after water storage based on the water source provided by the constant pressure water supply subsystem; the test soil box has an S-shaped water flow path inside, which is used to simulate the horizontal wetting front distance of the reservoir; and multiple capillary soil columns are arranged along the S-shaped water path to simulate the rising height of groundwater on both sides of the reservoir under the action of capillary force. Through the above structure, the embodiment of the present application realizes the simulation of reservoir immersion test in plain areas. The system has the characteristics of high space utilization, small filling volume, and can simulate reservoir immersion problems under various geological conditions.

Description

Technical Field

[0001] The present application relates to the field of geological engineering reservoir immersion research, and specifically to a reservoir immersion test simulation system and method. Background Art

[0002] After the reservoir is filled with water, the rock and soil of the reservoir bank are soaked by water and gradually become saturated, and the groundwater level rises accordingly, forming backwater (backwater refers to the phenomenon of rising water level due to obstruction of water flow). The submergence problem is the most important hydrogeological problem in the survey, design and construction of reservoirs in plain areas. For plain areas with binary sedimentary structures formed by alluvial deposits, reservoir submergence refers to the fact that after the reservoir is filled with water, the groundwater around the reservoir area is supported by the reservoir water, and the discharge is blocked, resulting in the groundwater level rising. Its main hazards are: (1) The impact of submergence on buildings: submergence will cause the foundation of buildings on the edge of the reservoir bank to be infiltrated and the strength to be reduced. (2) The impact of submergence on farmland: The rise in groundwater level causes the land to become swampy and salinized, and the cold soaking of rice fields causes crop yield reduction. (3) The impact of submergence on ecology: The impact of submergence on the ecological environment is mainly the formation of saline-alkali land and swamps. (4) The impact of submergence on geological conditions: submergence causes soil softening and reduced bearing capacity. The fluctuation of water level on the soil slope causes the slope to become unstable.

[0003] The problem of reservoir flooding is an important part of reservoir engineering survey. Severe reservoir flooding affects the selection of normal reservoir water level and even the selection of dam site. In response to the problem of reservoir flooding, researchers have carried out a large number of indoor simulation tests. However, since the impact of reservoir flooding on the surrounding area is relatively large, ranging from a few kilometers to tens of kilometers, the test model after scale miniaturization also requires a larger test site, and the workload of soil filling for the test is also large. Summary of the invention

[0004] The embodiment of the present application provides a reservoir immersion test simulation system and method, which has the characteristics of high space utilization, small filling volume, and ability to simulate reservoir immersion problems under various geological conditions, and can overcome the above-mentioned technical problems.

[0005] In order to solve the above problems, the present application embodiment discloses a reservoir immersion test simulation system, including:

[0006] Constant pressure water supply subsystem, water storage chamber, test soil box and capillary soil column;

[0007] The constant pressure water supply subsystem is used to supply water to the water storage chamber under a preset water head according to the requirements of the reservoir immersion test;

[0008] The water storage chamber comprises a water inlet and a water outlet, wherein the water inlet is connected to the water outlet of the constant pressure water supply subsystem, and the water outlet is connected to the test soil box;

[0009] The test soil box is provided with an S-shaped water flow path inside, and the S-shaped water flow path is filled with test soil in layers from bottom to top, and the test soil is a saturated gravel layer and an unsaturated soil layer from bottom to top, wherein the water inlet of the S-shaped water flow path is connected to the water outlet of the water storage chamber, so as to simulate the wetting front distance of the reservoir in the horizontal direction;

[0010] A plurality of the capillary soil columns are arranged along the S-shaped water flow path, wherein the capillary soil columns are vertically arranged at the inner bottom of the test soil box, and the capillary soil columns are filled with the test soil to simulate the rising height of groundwater on both sides of the reservoir under the action of capillary force.

[0011] In one embodiment of the present application, the test soil box comprises:

[0012] A baffle is arranged in the test soil box, and a plurality of the baffles are arranged in parallel along the long side of the test soil box at a preset interval to divide the test soil box into a plurality of interconnected soil trough sub-units;

[0013] Among them, one end of the baffle is sealed with the inner wall of a long side of the test soil box, and the other end is provided with a water-permeable area, which is communicated with two adjacent soil trough sub-units to form the S-shaped water flow path.

[0014] In one embodiment of the present application, the water permeable area includes a card slot and a water permeable hole, wherein:

[0015] The slot is formed by the end surface of the baffle plate and the inner wall of the other long side of the test soil box, and is used to install the capillary soil column;

[0016] A plurality of water-permeable holes are located on the plate surface of the baffle plate and are arranged close to the card slot, and the water-permeable holes are communicated with two adjacent soil trough sub-units.

[0017] In one embodiment of the present application, the capillary soil column is also provided at the center position of each soil trough sub-unit.

[0018] In one embodiment of the present application, the width of the soil trough subunit has a preset ratio value to the long side of the test soil box.

[0019] In one embodiment of the present application, the capillary soil column includes a permeable section and a non-permeable section, wherein:

[0020] The permeable section is vertically arranged at the inner bottom of the test soil box, and the impermeable section is higher than the upper surface of the unsaturated soil layer and communicates with the atmosphere.

[0021] In one embodiment of the present application, the top end surface of the baffle and the top end surfaces of the two side plates of the test soil box parallel to the baffle are both provided with scales.

[0022] In one embodiment of the present application, in a reservoir immersion test under simulated non-pressurized water head conditions, the water outlet end of the water storage chamber and the highest point of the permeable area are slightly lower than the upper surface of the unsaturated soil layer;

[0023] In a reservoir immersion test under simulated pressure head conditions, when the gas outlet of the Martens flask in the constant pressure water supply subsystem is higher than the upper surface of the saturated gravel layer and lower than the upper surface of the unsaturated soil layer, the water outlet end of the water storage chamber and the area of ​​the permeable area higher than the upper surface of the saturated gravel layer are in an impermeable state, and the water outlet end of the water storage chamber and the area of ​​the permeable area lower than the upper surface of the saturated gravel layer are in a permeable state;

[0024] In a reservoir immersion test under simulated pressurized head conditions, when the air outlet of the Malchow flask in the constant pressure water supply subsystem is higher than the upper surface of the unsaturated soil, the water outlet end of the water storage chamber and the area of ​​the permeable area higher than the upper surface of the saturated gravel layer are in an impermeable state, and the top of the water storage chamber is covered and sealed.

[0025] In one embodiment of the present application, a water level observation line is provided on the outer wall of the water storage chamber.

[0026] In order to solve the above problems, the present application also discloses a reservoir immersion test simulation method, which includes:

[0027] Under a preset water head, a reservoir immersion test is carried out using the reservoir immersion test simulation system as described in the embodiment of the present application;

[0028] In the reservoir immersion test, the distance of the wetting front of the reservoir in the horizontal direction is measured according to the infiltration conditions in the S-shaped water flow path of the test soil box, and the rising height of the groundwater on both sides of the reservoir under the action of capillary force is measured according to the water level conditions in the capillary soil column;

[0029] The groundwater backfill head line is calculated based on the thickness of the saturated gravel layer in the test soil box, the permeability coefficient of the saturated gravel layer, the permeability coefficient of the unsaturated soil layer, the air outlet height of the Malchow flask in the constant pressure water supply subsystem before and after water storage, the horizontal wetting front distance of the reservoir measured before and after the section is backfilled, and the rising height of groundwater on both sides of the reservoir under the action of capillary force measured before and after the section is backfilled.

[0030] The embodiments of the present application include the following advantages:

[0031] The reservoir immersion test simulation system of the embodiment of the present application includes a constant pressure water supply subsystem, a water storage chamber, a test soil box, a capillary soil column and other structures, wherein the constant pressure water supply subsystem is used to supply water to the water storage chamber under a preset water head according to the needs of the reservoir immersion test; the water storage chamber is used to simulate the reservoir; an S-shaped water flow path is arranged inside the test soil box, and the S-shaped water flow path is filled with test soil in layers from bottom to top, and the test soil is a saturated gravel layer and an unsaturated soil layer from bottom to top, wherein the water inlet of the S-shaped water flow path is connected to the water outlet of the water storage chamber, and is used to simulate the wetting front distance of the reservoir in the horizontal direction. ; A plurality of capillary soil columns are arranged along the S-shaped water flow path, wherein the capillary soil columns are vertically arranged at the inner bottom of the test soil box, and the capillary soil columns are filled with the test soil to simulate the rising height of groundwater on both sides of the reservoir under the action of capillary force; the test soil box with an S-shaped water flow path in the embodiment of the present application is used to greatly save the space required for the test model in the horizontal direction, and the soil layer above the groundwater level is replaced by filling with capillary soil columns with a smaller inner diameter, which greatly reduces the amount of soil used for the test; the system has the characteristics of high space utilization, small filling volume, and can simulate reservoir submergence problems under various geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1(a) is a schematic diagram of the reservoir submerged area when water is replenished from both banks to the reservoir;

[0034] Figure 1(b) is a schematic diagram of the reservoir submerged area when the reservoir replenishes water to both banks;

[0035] Figure 2 It is a schematic diagram of the overall structure of a reservoir immersion test simulation system according to an embodiment of the present application;

[0036] Figure 3 It is a structural schematic diagram of the constant pressure water supply subsystem of an embodiment of the present application;

[0037] FIG4( a ) is a schematic diagram of the cross-sectional structure of a test soil box in a reservoir immersion test according to an embodiment of the present application;

[0038] FIG4( b ) is a schematic diagram of an S-shaped water flow path in the test soil box shown in FIG4( a ) of an embodiment of the present application;

[0039] FIG4(c) is a schematic diagram of the location of the capillary soil column in the test soil box shown in FIG4(a) of the embodiment of the present application;

[0040] Figure 5 It is a schematic diagram of the structure of the test soil box of the embodiment of the present application;

[0041] Figure 6 It is a schematic diagram of the structure of the capillary soil column of the embodiment of the present application;

[0042] Figure 7 It is a step flow chart of a reservoir immersion test simulation method according to an embodiment of the present application.

[0043] Description of reference numerals:

[0044] 1-constant pressure water supply subsystem, 101-Martin flask, 102-weighing sensor, 103-paperless recorder; 104-load-bearing bracket, 105-water outlet valve, 106-water inlet pipe, 1041-Martin flask slot;

[0045] 2- Water storage room;

[0046] 3-test soil box, 301-baffle, 302-soil trough subunit, 303-card slot, 304-water permeable hole;

[0047] 4-capillary soil column, 401-permeable section, 402-impermeable section;

[0048] 5- Ruler. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] This application analyzes the current flooding problem of plain reservoirs. There are two situations in which the flooding of plain reservoirs exists:

[0051] 1. The surrounding groundwater level is higher than the reservoir water level. This situation generally occurs in the alluvial fan area near the piedmont transition zone. The groundwater is replenished from the gentle slope of the high terrain to the reservoir in the low terrain. The groundwater level in the piedmont transition zone is often higher than the reservoir water level. The farther from the center of the reservoir, the higher the groundwater level. Referring to Figure 1 (a), it is a schematic diagram of the reservoir submerged area when the two banks replenish water to the reservoir in an application example of this application.

[0052] As shown in Figure 1(a), in this application example, M is the thickness of the lower saturated gravel layer (unit: m); K s is the permeability coefficient of the saturated gravel layer (unit: m / d); Kr is the permeability coefficient of the clay layer in the upper aeration zone (unit: m / d); h and H are the thickness from the reservoir / river water level to the top surface of the saturated zone gravel layer before and after the reservoir / river section is filled (unit: m). 地下水 and L 地下水 are the thickness from the groundwater level to the top surface of the saturated gravel layer before and after the cross-section backwatering (unit: m), see the dotted line in Figure 1(a); l 毛细水 and L 毛细水 They are the thickness (m) from the capillary water level in the underground soil to the top surface of the saturated gravel layer before and after the cross-section is flooded, see the solid line in Figure 1(a).

[0053] 2. The water level in the reservoir area is higher than the surrounding groundwater level. This situation usually occurs in plain areas. The water level in the reservoir is generally higher than the surrounding groundwater level. The farther away from the center of the reservoir, the lower the groundwater level. Referring to Figure 1(b), it is a schematic diagram of the reservoir submerged area in an application example of this application when the reservoir replenishes water to both banks.

[0054] As shown in Figure 1(b), in this application example, M is the thickness of the lower permeable gravel layer (unit: m); K s is the permeability coefficient of the permeable gravel layer (unit: m / d); K r is the permeability coefficient of the upper permeable clay layer (unit: m / d); h and H are the thickness from the reservoir / river water level to the top surface of the permeable gravel layer before and after the reservoir / river section is filled with water (unit: m). 地下水 and L 地下水 are the thickness from the groundwater level to the top of the permeable gravel layer before and after waterlogging (unit: m), see the dotted line in Figure 1(b); l 毛细水 and L 毛细水 They are the thickness from the capillary water level in the underground soil to the top surface of the permeable gravel layer before and after the cross-section is flooded (unit: m), see the solid line in Figure 1(b).

[0055] Based on the above analysis, the present application embodiment proposes a reservoir immersion test simulation system, which can be used for the simulation and research of the plain reservoir immersion problem under the above two application examples. Figure 2 to Figure 6 .

[0056] Reference Figure 2 , showing the overall structural diagram of a reservoir immersion test simulation system according to an embodiment of the present application, the immersion test simulation system may include: a constant pressure water supply subsystem 1, a water storage chamber 2, a test soil box 3 and a capillary soil column 4;

[0057] The constant pressure water supply subsystem 1 is used to supply water to the water storage chamber 2 under a preset water head according to the requirements of the reservoir immersion test;

[0058] The water storage chamber 2 includes a water inlet and a water outlet, the water inlet is connected to the water outlet valve on the constant pressure water supply subsystem 1, and the water outlet is connected to the test soil box 3;

[0059] The test soil box 3 is provided with an S-shaped water flow path inside, and the S-shaped water flow path is filled with test soil in layers from bottom to top. The test soil is a saturated gravel layer and an unsaturated soil layer from bottom to top, wherein the water inlet of the S-shaped water flow path is connected to the water outlet of the water storage chamber 2, so as to simulate the wetting front distance of the reservoir in the horizontal direction;

[0060] A plurality of capillary soil columns 4 are arranged along the S-shaped water flow path, wherein the capillary soil columns 4 are vertically arranged at the inner bottom of the test soil box 3, and the capillary soil columns 4 are filled with the test soil to simulate the rising height of groundwater on both sides of the reservoir under the action of capillary force.

[0061] Reference Figure 3 The constant pressure water supply subsystem 1 of the embodiment of the present application includes a Martens flask 101, a weighing sensor 102 placed at the bottom of the Martens flask 101, a paperless recorder 103, a load-bearing bracket 104 and other components. The Martens flask 101 is a device based on the principle of a communicating vessel, which makes the pressure inside and outside the container consistent, thereby achieving a constant water head and automatic water replenishment in the Martens flask 101. Specifically, the Malchnitz flask 101 may include: a Malchnitz flask body (not marked in the figure), which is provided with a bottle mouth; an elastic sealing plug (not marked in the figure), which is installed in the bottle mouth and has radial pressure on the bottle mouth; an air inlet capillary (not marked in the figure), the upper end of which is an air inlet, the lower end of which is an air outlet and the end surface of which passes through the elastic sealing plug and is placed in the Malchnitz flask body, and the air inlet is communicated with the inner cavity of the Malchnitz flask body; a water outlet (not marked in the figure), the water outlet is provided with a water outlet valve 105, and the water outlet valve 105 is communicated with the water inlet end below the water storage chamber 2 through a water inlet pipe 106. The load-bearing bracket 104 includes a vertical rod, a load-bearing plate and a Martens flask slot 1041. The vertical rod is vertically fixed to the load-bearing plate. The Martens flask slot 1041 and the paperless recorder 103 are installed on the vertical rod. The weighing sensor 102 is installed in the Martens flask slot 1041. The Martens flask 101 is placed in the Martens flask slot 1041 and is located on the weighing sensor 102. In addition, a handle is provided on the vertical rod, and a universal wheel is provided at the bottom of the load-bearing plate to facilitate pushing the bracket to move the constant pressure water supply subsystem 1.

[0062] In the embodiment of the present application, by adjusting the height of the air outlet, the water infiltration head between the Malchnitz flask 101 and the water storage chamber 2 can be adjusted, so that the Malchnitz flask 101 can supply water to the water storage chamber 2 according to the preset water head. Among them, by adjusting the height of the Malchnitz flask slot 1041 on the vertical rod, the coarse adjustment of the height of the air outlet in the Malchnitz flask 101 can be achieved; by pulling the air inlet capillary up and down in the vertical direction, the fine adjustment of the height of the air outlet in the Malchnitz flask 101 can be achieved. After opening the water outlet valve 105, the Malchnitz flask 101 supplies water to the water storage chamber 2. During the water supply process, the weighing sensor 102 collects the mass data of the Malchnitz flask 101 in real time, and then transmits the mass data to the paperless recorder 103, which records the mass data, so that the mass change data of the water supply process of the Malchnitz flask 101 can be monitored in real time and automatically recorded, which effectively saves manpower. By converting the collected data of the mass change of the Martens flask 101 into the amount of water entering the test soil box 3, the permeability coefficient of the groundwater in the reservoir submerged area can be easily obtained according to the permeability coefficient calculation formula. Further, the user can make a time prediction of the impact range of the submerged area according to the permeability coefficient.

[0063] The water storage chamber 2 is used to simulate a reservoir / river based on the water source provided by the Malvern flask 101. The water level in the water storage chamber 2 before and after water storage corresponds to the water level of the reservoir / river before and after water storage. Figure 2 , Figure 4(a) and Figure 5 The water storage chamber 2 is connected to the test soil box 3 and the Malvern flask 101 respectively. The water storage chamber 2 and the test soil box 3 can be integrally formed, that is, the water outlet of the water storage chamber 2 is arranged on a short side plate of the test soil box 3. The water outlet of the water storage chamber 2 includes a plurality of water permeable holes arranged on the short side plate of the test soil box 3, and the water permeable holes are connected to the inside of the test soil box 3, which are used to simulate the physical phenomenon of water flow penetrating from a reservoir or a river to both banks. A water level observation line is also arranged on the outer wall of the water storage chamber 2, which is convenient for determining the water level height in the water storage chamber 2 before and after water storage.

[0064] The test soil box 3, referring to FIG4(a), is filled with the test soil required for the test from bottom to top, so as to observe the horizontal movement distance of water in the clay layer (permeable clay layer) of the air-entraining zone before and after the reservoir is backfilled, in other words, the horizontal impact range of the reservoir backfilling on the surrounding groundwater. The test soil is divided into at least two layers, the lower layer is a saturated gravel layer, which is used to simulate the saturated gravel layer or permeable gravel layer in FIG1(a) and FIG1(b); the upper layer is an unsaturated soil layer, which is used to simulate the clay layer or permeable clay layer in FIG1(a) and FIG1(b).

[0065] like Figure 5As shown, in one embodiment of the present application, the test soil box 3 includes: a baffle 301, which is arranged in the test soil box 3, and a plurality of baffles 301 are arranged in parallel along the long side of the test soil box 3 at a preset interval, dividing the test soil box 3 into a plurality of soil trough sub-units 302 that are interconnected; wherein one end of the baffle 301 is sealed with the inner side wall of one long side of the test soil box 3, and the other end is provided with a water-permeable area, which is connected to two adjacent soil trough sub-units 302 to form the S-shaped water flow path. In the embodiment of the present application, water flows from Figure 5 The water outlet of the water storage chamber 2 shown enters the first soil trough subunit 302, and then passes through the permeable area in the baffle 301 and flows to the next soil trough subunit 302 in an S-shaped water flow path. Among them, the top surface of the baffle 301 and the top surfaces of the two side plates of the test soil box 3 parallel to the baffle 301 are provided with a scale 5. The path of water flowing through each soil trough subunit 302 from the water outlet of the water storage chamber 2 is added up to be the wet front distance of the reservoir / river in the horizontal direction.

[0066] 4(b) and 4(c), assuming that the length of the test soil box 3 (ie, the length of the long side) is S 1 , the inner width of the test soil box 3 is S 3 (S 3 The test soil box 3 has n soil trough subunits 302, and the width of each soil trough subunit 302 is S 2 , the wall thickness of the baffle 301 is Δh. If the water in the water storage chamber 2 penetrates to the P scale (not shown) position of the mth soil trough subunit 302 at a certain head and a certain time (P is the distance calculated from the water flow direction), ignoring the wall thickness of the baffle 301, the wetting front distance (i.e., the influence distance before and after waterlogging) at this time and under this head condition is (m-1)×S 2 In practice, if a two-dimensional test soil box 3 is used to conduct the test on a reservoir or river, at least n×S 2 The length of the soil box is only S. 1 Ignoring the wall thickness of the soil box and the wall thickness of the baffle 301, the length of the test soil box 3 of the embodiment of the present application is only S of the length of the two-dimensional test box. 1 / (n×S 3 +Δh), which greatly saves the space required for the test model in the horizontal direction.

[0067] During specific implementation, the user can set the number of soil trough sub-units 302 according to the requirements of the test plan, and the baffle 301 can be set to be fixed or detachable. When the baffle 301 is fixedly connected to the test soil box 3, the baffle 301 can be integrally connected to the test soil box 3; when the baffle 301 is detachably connected to the test soil box 3, the baffle 301 and the test soil box 3 can be connected by a mortise and tenon structure. In addition, considering the impact of the fill volume and the side wall effect on the diffusion of water flow, the width of the soil trough sub-unit 302 and the long side of the test soil box 3 have a preset ratio value, and the preset ratio value can be set according to actual test requirements, such as 1 / 4, 1 / 5, 1 / 6, etc. Optionally, the ratio of the width of the soil trough sub-unit 302 to the long side length of the test soil box 3 is 1:5, that is, S 2 / S 1 =1 / 5. Under this preset ratio, the width of the soil trough subunit 302 will not be too large, thereby avoiding excessive filling volume; at the same time, the width of the soil trough subunit 302 will not be too small, thereby reducing the influence of the side wall effect on water flow diffusion.

[0068] In one embodiment of the present application, each baffle 301 and the water-permeable area set between the baffle 301 and the test soil box 3 include a slot 303 and a water-permeable hole 304, wherein: the slot 303 is formed by the end face of the baffle 301 and the inner wall of the other long side of the test soil box 3, and is used to install the capillary soil column 4; a plurality of water-permeable holes 304 are located on the plate surface of the baffle 301 and are arranged close to the slot 303, and the water-permeable holes 304 are connected to two adjacent soil trough sub-units 302. Figure 5 As shown, one end face of the baffle 301 does not contact the side wall of the test soil box 3 and is a concave arc surface. Correspondingly, there are also multiple concave arc strips on the side wall of the test soil box 3. The concave arc strips correspond to the concave arc surface one by one, and the two can form a circular slot 303 for installing the capillary soil column 4. The concave arc strips and the concave arc surface can effectively limit and fix the position of the capillary soil column 4 to prevent it from loosening. Multiple water-permeable holes 304 can be neatly arranged on the baffle 301, such as Figure 5 As shown, they are arranged in a rectangular structure to ensure uniform water penetration.

[0069] The capillary soil column 4 is used to fill the test soil and observe the rising height of capillary water in the permeable clay layer / vadose zone clay layer before and after the reservoir is filled with water, so as to simulate the rising height of groundwater on both sides of the reservoir / river under the action of capillary force. Figure 6 The capillary soil column 4 includes a permeable section 401 and a non-permeable section 402, wherein: the permeable section 401 is vertically arranged at the inner bottom of the test soil box 3, and the non-permeable section 402 is higher than the upper surface of the unsaturated gravel layer and communicates with the atmosphere.

[0070] In various embodiments of the present application, capillary water refers to water retained in the capillary pores of the soil by capillary force, that is, when the soil water content gradually increases, the part of water that exceeds the maximum molecular water holding capacity will be retained in the capillary pores of the soil under the action of capillary force. Inserting the permeable section 401 of the capillary soil column 4 into the soil can facilitate the water in the saturated gravel layers to flow smoothly in the S-shaped water flow path. The impermeable section 402 can facilitate the observation of the water level changes of the capillary water in the soil before and after the waterlogging. For the convenience of observation, the capillary soil column 4 can be made of a transparent plexiglass tube, and the impermeable section 402 of the capillary soil column 4 is provided with a scale 5.

[0071] In one embodiment of the present application, in addition to providing capillary soil columns 4 at each inflection point of the S-shaped water flow path, the present application may also provide capillary soil columns 4 at other positions of the S-shaped water flow path. The user may increase or decrease the number of capillary soil columns 4 according to actual conditions, and the present application does not limit this. Of course, the shorter the distance between the capillary soil columns 4, that is, the shorter the spatial sampling step, the more the capillary water level rise height curve of each capillary soil column 4 can truly reflect the distribution of capillary water in the formation. Optionally, referring to Figures 4(b) and 4(c), the present application provides a capillary soil column 4 at the center of each soil trough subunit 302, that is, the spacing between the capillary soil columns 4 is S. 3 / 2.

[0072] In practice, reservoir flooding can be divided into two types: confined head (the upper clay in the unsaturated soil layer is a relatively impermeable layer. Under a certain head, the lower confined water overcomes the resistance and gravity and penetrates upward along the clay for a certain distance. As the seepage path lengthens, the decrease in seepage pressure gradually tends to equilibrium.) and unconfined head infiltration. Confined or unconfined depends on the geology and structure. For example, there is a weak permeable layer or an impermeable layer on the upper part of the saturated gravel layer, or the water level of the river reservoir is higher than the soil surface. Generally speaking, when the river / reservoir water level is higher than the groundwater level (also called the groundwater level), and the river / reservoir can only replenish water to the soil upward through the saturated underground layer, it is a reservoir flooding under confined conditions. When the river / reservoir water level is lower than the groundwater level or higher than the groundwater level, it can also replenish water from the shore to both sides, which is a reservoir flooding under unconfined conditions.

[0073] In an embodiment of the present application, in a reservoir immersion test simulating non-pressurized water head conditions, the water outlet end of the water storage chamber 2 and the highest point of the permeable area are slightly lower than the upper surface of the unsaturated soil layer to prevent the water in the water storage chamber 2 from flowing away from the soil surface and then seeping downward.

[0074] In a reservoir immersion test under simulated pressure head conditions, when the gas outlet of the Malchnitz flask 101 in the constant pressure water supply subsystem 1 is higher than the upper surface of the saturated gravel layer and lower than the upper surface of the unsaturated soil layer, the water outlet end of the water storage chamber 2 and the area of ​​the permeable area above the upper surface of the saturated gravel layer are in a non-permeable state, and the water outlet end of the water storage chamber 2 and the area of ​​the permeable area below the upper surface of the saturated gravel layer are in a permeable state; and when the gas outlet of the Malchnitz flask 101 in the constant pressure water supply subsystem 1 is higher than the upper surface of the unsaturated soil, the water outlet end of the water storage chamber 2 and the area of ​​the permeable area above the upper surface of the saturated gravel layer are in a non-permeable state, and the top of the water storage chamber 2 is sealed with a cover. Specifically, the water outlet end of the water storage chamber 2 and the water permeable area above the saturated gravel layer can be blocked with waterproof tape. Covering and sealing the top surface of the water storage chamber 2 can prevent water from overflowing.

[0075] In summary, based on the above structure, the embodiment of the present application has the following two characteristics: First, it saves space in the length direction of the test. Due to the large impact radius of the reservoir immersion area, even if the test is carried out indoors at a miniature scale, the traditional two-dimensional test still requires a long soil box, and the general laboratory space is difficult to meet the requirements. The test soil box 3 with an S-shaped water flow path in the embodiment of the present application greatly saves the space required for the test model in the horizontal direction, overcoming the above difficulties. Second, it saves the amount of soil used for the test. The traditional two-dimensional test measures the height of the capillary water level rise, and the part above the groundwater level needs to be filled with soil (the thickness of the fill is calculated based on the capillary water rise, which is generally greater than the capillary water rise). For indoor tests under undisturbed soil conditions, the workload of field soil collection is large, and the embodiment of the present application uses a capillary soil column 4 with a smaller inner diameter to fill the soil to replace the soil layer above the groundwater level, which greatly reduces the amount of soil used for the test (when taking soil in the field, it is only necessary to press the capillary soil column 4 into the soil layer at the sampling point, and the sampling workload is small and easy to operate).

[0076] Based on the same inventive concept, Figure 7 The present application embodiment proposes a reservoir immersion test simulation method, which may include the following steps:

[0077] Step S1: Under a preset water head, a reservoir immersion test is carried out using the reservoir immersion test simulation system as described in the embodiment of the present application;

[0078] Step S2: In the reservoir immersion test, the wetting front distance of the reservoir in the horizontal direction is measured according to the infiltration conditions in the S-shaped water flow path of the test soil box 3, and the rising height of the groundwater on both sides of the reservoir under the action of capillary force is measured according to the water level conditions in the capillary soil column 4;

[0079] Step S3: Calculate the groundwater head line according to the thickness of the saturated gravel layer in the test soil box 3, the permeability coefficient of the saturated gravel layer, the permeability coefficient of the unsaturated soil layer, the height of the air outlet of the Malchow flask 101 in the constant pressure water supply subsystem 1 before and after water storage, the horizontal wetting front distance of the reservoir measured before and after the section is backfilled, and the rising height of the groundwater on both sides of the reservoir under the action of capillary force measured before and after the section is backfilled.

[0080] First of all, before the experiment is carried out, the following preparations need to be done:

[0081] 1: Fill the soil.

[0082] The user fills the test soil into the test soil box 3 and the capillary soil column 4 according to the test plan. When it is necessary to carry out a reservoir immersion test under the original soil condition, the user can use the detachable soil trough subunit 302 of the embodiment of the present application to assemble the soil indoors for field soil collection. If it is inconvenient to collect the original soil in the field, the user can fill the test soil box 3 and the capillary soil column 4 with disturbed soil in layers according to the soil layer distribution of field geological exploration (soil layer thickness, soil quality, bulk density, water content, etc. after scale reduction), as shown in 4 (a).

[0083] It should be noted that if an original soil test is carried out, the capillary soil column 4 of the plexiglass has a low strength and cannot be used directly for soil collection. It is necessary to use a metal soil collector / drill to collect soil in the field. The retrieved soil is then cut according to the shape of the test soil box 3 and the capillary soil column 4. The surface of the soil after cutting will become smooth. When water passes through this smooth surface, the penetration and diffusion of water in the soil will be affected. Therefore, it is necessary to roughen the soil of the water-passing section during the filling process (such as the soil at the junction of the upper and lower layers or adjacent layers of the soil trough subunit 302).

[0084] 2: Adjust the water head.

[0085] Refer to Figure 1(a) or Figure 1(b). The user adjusts the reservoir water level according to the test plan. Figure 3 The height of the Malchow flask 101 on the vertical rod and / or the height of the air outlet in the constant pressure water supply subsystem 1.

[0086] In step S1 and step S2, after the test starts, the user records the distance of the wetting front of the water in the horizontal direction in the test soil box 3 and the height of the water in the capillary soil column 4 in the vertical direction. Since the volume of the water storage chamber 2 is large, it takes a certain time for the water from the Malchnitz flask 101 to flow to the set height of the water storage chamber 2, and it will also consume a part of the water in the cavity of the Malchnitz flask 101. Therefore, the embodiment of the present application can use a large flow water injector to directly add water to the water storage chamber 2, add water to a position close to the set water level, and then open the water outlet valve 105 of the Malchnitz flask 101, which can shorten the water filling time of the Malchnitz flask 101. When the height of the air outlet of the Malchnitz flask 101 is flush with the set water level height of the water storage chamber 2, the water supply from the Malchnitz flask 101 to the water storage chamber 2 stops. As the water penetrates and diffuses in the soil, the water level of the water storage chamber 2 drops, and the Malchnitz flask 101 supplies water to the water storage chamber 2 again, thereby ensuring that the water levels of the Malchnitz flask 101 and the water storage chamber 2 are in a dynamic equilibrium state.

[0087] Next, execute step S3 to calculate the water head line. The user can select the Kaminsky method, the reduction coefficient method considering the initial hydraulic gradient, or the numerical method to determine the groundwater level in the unsaturated soil layer based on the thickness of the saturated gravel layer, the permeability coefficient of the saturated gravel layer, the permeability coefficient of the unsaturated soil layer, the height of the outlet of the Malchow flask 101 before and after water storage, the distance of the wetting front of the reservoir in the horizontal direction before and after water storage, and the rising height of the groundwater on both sides of the reservoir under the action of capillary force before and after water storage. Any of the above three methods can be used, and there is no distinction between good and bad. The specific method to be used to calculate the groundwater level can be determined based on the actual geological conditions, and the embodiments of this application are not limited here.

[0088] In an application example of this application, the Kaminski method is used as an example, and the groundwater head height L 地下水 The calculation formula is as follows:

[0089] 2K S M(l 地下水 -h)+K r (l 地下水 2 -h 2 )=2K S M(L 地下水 -H)+K r (L 地下水 2 -H 2 ) (1);

[0090] The groundwater head height L calculated according to the above formula (1) is 地下水 , combined with the hydrodynamic method, the following groundwater head line equation can be derived:

[0091]

[0092] In the above formula, M is the thickness of the saturated gravel layer (unit: m); K s is the permeability coefficient of the saturated gravel layer (unit: m / d); K r is the permeability coefficient of the unsaturated soil layer (unit: m / d); h and H are the water level heights before and after the reservoir is filled (unit: m); l 地下水 and L 地下水 are the thickness of the groundwater level to the upper surface of the saturated soil layer before and after the cross-section is flooded (unit: m) (there are many methods for measuring groundwater, such as radar water level meter or installing water level sensors in water level observation wells, etc.); l 毛细水 and L 毛细水 are the simulated rising heights of groundwater on both sides of the reservoir under the action of capillary force before and after the cross-section backwatering (unit: m); L x is the groundwater level at point x in the horizontal direction after backwatering (unit: m), i.e., the groundwater level at point x on the S-shaped water flow path in the embodiment of the present application); ΔP is the height of the plant root system or the building foundation (m).

[0093] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0094] It should also be noted that, in this article, the orientation or position relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations, nor can they be understood as indicating or implying relative importance. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. Without more restrictions, an element defined by the phrase "comprising a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device comprising the element.

[0095] The technical solution provided by the present application is described in detail above. The principle and implementation method of the present application are described in this article using specific examples. The description of the above embodiments is only used to help understand the present application, and the content of this specification should not be understood as limiting the present application. At the same time, for those of ordinary skill in the art, according to the present application, there will be different forms of changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived therefrom are still within the scope of protection of the present application.

Claims

1. A reservoir immersion test simulation system, characterized in that: include: A constant pressure water supply subsystem (1), a water storage chamber (2), a test soil box (3) and a capillary soil column (4); The constant pressure water supply subsystem (1) is used to supply water to the water storage chamber (2) at a preset water head according to the requirements of the reservoir immersion test; The water storage chamber (2) comprises a water inlet and a water outlet, the water inlet being in communication with the water outlet of the constant pressure water supply subsystem (1), and the water outlet being in communication with the test soil box (3); The test soil box (3) is provided with an S-shaped water flow path inside, and the S-shaped water flow path is filled with test soil in layers from bottom to top, and the test soil is composed of a saturated gravel layer and an unsaturated soil layer from bottom to top, wherein the water inlet of the S-shaped water flow path is connected to the water outlet of the water storage chamber (2), so as to simulate the wetting front distance of the reservoir in the horizontal direction; A plurality of capillary soil columns (4) are arranged along the S-shaped water flow path, wherein the capillary soil columns (4) are vertically arranged at the inner bottom of the test soil box (3), and the capillary soil columns (4) are filled with the test soil to simulate the rising height of groundwater on both sides of the reservoir under the action of capillary force; Wherein, the test soil box (3) comprises: A baffle (301) is arranged in the test soil box (3), and a plurality of the baffles (301) are arranged in parallel along the long side of the test soil box (3) at a preset interval, so as to divide the test soil box (3) into a plurality of soil trough sub-units (302) that are interconnected; One end of the baffle (301) is sealed with an inner wall of a long side of the test soil box (3), and the other end is provided with a water-permeable area, and the water-permeable area is communicated with two adjacent soil trough sub-units (302) to form the S-shaped water flow path; The water-permeable area includes a card slot (303) and a water-permeable hole (304), wherein: The clamping groove (303) is formed by the end surface of the baffle (301) and the inner wall of the other long side of the test soil box (3), and is used for installing the capillary soil column (4); A plurality of water-permeable holes (304) are located on the plate surface of the baffle plate (301) and are arranged close to the clamping groove (303), and the water-permeable holes (304) are communicated with two adjacent soil trough sub-units (302); Wherein, the capillary soil column (4) comprises a permeable section (401) and a non-permeable section (402); The water-permeable section (401) is vertically arranged at the inner bottom of the test soil box (3), and the water-impermeable section (402) is higher than the upper surface of the unsaturated soil layer and communicates with the atmosphere; Wherein, the top end surface of the baffle (301) and the top end surfaces of the two side plates of the test soil box (3) parallel to the baffle (301) are both provided with a scale (5); Wherein, in a reservoir immersion test under simulated non-pressure head conditions, the water outlet end of the water storage chamber (2) and the highest point of the permeable area are slightly lower than the upper surface of the unsaturated soil layer; In a reservoir immersion test under simulated pressure head conditions, when the air outlet of the Malchnitz flask (101) in the constant pressure water supply subsystem (1) is higher than the upper surface of the saturated gravel layer and lower than the upper surface of the unsaturated soil layer, the water outlet end of the water storage chamber (2) and the area of ​​the permeable area higher than the upper surface of the saturated gravel layer are in a non-permeable state, and the water outlet end of the water storage chamber (2) and the area of ​​the permeable area lower than the upper surface of the saturated gravel layer are in a permeable state; In a reservoir immersion test under simulated pressure head conditions, when the air outlet of the Malchnitz flask (101) in the constant pressure water supply subsystem (1) is higher than the upper surface of the unsaturated soil, the water outlet end of the water storage chamber (2) and the area of ​​the permeable area higher than the upper surface of the saturated gravel layer are in a non-permeable state, and the top of the water storage chamber (2) is sealed with a cover; The baffle (301) is integrally formed with the test soil box (3) to be fixedly connected, or is detachably connected to the test soil box (3) via a mortise and tenon structure.

2. The system according to claim 1, characterized in that The capillary soil column (4) is also arranged at the center of each soil trough subunit (302).

3. The system according to any one of claims 1 to 2, characterized in that: The width of the soil trough subunit (302) and the long side of the test soil box (3) have a preset ratio value.

4. The system according to claim 1, characterized in that A water level observation line is arranged on the outer wall of the water storage chamber (2).

5. A reservoir immersion test simulation method, characterized in that: The method comprises: Under a preset water head, a reservoir immersion test is carried out using the reservoir immersion test simulation system as described in any one of claims 1 to 4; In the reservoir immersion test, the distance of the wetting front of the reservoir in the horizontal direction is measured according to the infiltration conditions in the S-shaped water flow path of the test soil box (3), and the rising height of the groundwater on both sides of the reservoir under the action of capillary force is measured according to the water level conditions in the capillary soil column (4); The groundwater head line is calculated based on the thickness of the saturated gravel layer in the test soil box (3), the permeability coefficient of the saturated gravel layer, the permeability coefficient of the unsaturated soil layer, the air outlet height of the Malchnitz flask (101) in the constant pressure water supply subsystem (1) before and after water storage, the horizontal wetting front distance of the reservoir measured before and after the cross section is backfilled, and the rising height of the groundwater on both sides of the reservoir under the action of capillary force measured before and after the cross section is backfilled; Before carrying out the reservoir immersion test, the process also includes filling soil and adjusting the water head, specifically including: During the process of filling the soil, roughening the soil of the water-passing section is performed, wherein the soil of the water-passing section includes the soil at the junction of the upper and lower layers or adjacent layers of the soil trough subunits (302); According to the reservoir water level requirements in the test plan, the height of the Malchnitz flask (101) on the vertical rod and / or the height of the air outlet in the constant pressure water supply subsystem (1) are adjusted.

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