阅读说明：本技术 一种模拟复杂条件下岩土边坡失稳破坏的模型试验装置 (Model test device for simulating instability and damage of rock-soil slope under complex condition ) 是由 王光进 艾啸韬 纪翠翠 刘文连 杨溢 许汉华 陈志斌 眭素刚 聂闻 丁飞 孔祥云 于 2019-09-27 设计创作，主要内容包括：本发明公开一种模拟复杂条件下岩土边坡失稳破坏的模型试验装置,属于岩土工程及采矿工程技术领域,该模型试验装置,包括风雨模拟系统,地震模拟系统,相似模型试验系统、监测系统；本装置能够高效地进行排土场、尾矿坝等岩土边坡体的相似模型试验,研究分析边坡体分别在降雨、地震以及两者耦合作用下边坡体的稳定性及其破坏模式。(The invention discloses a model test device for simulating instability and damage of a rock-soil slope under complex conditions, which belongs to the technical field of geotechnical engineering and mining engineering, and comprises a wind and rain simulation system, an earthquake simulation system, a similar model test system and a monitoring system; the device can efficiently perform similar model tests of rock soil slope bodies such as a refuse dump, a tailing dam and the like, and research and analyze the stability and the damage mode of the slope bodies under the coupling action of rainfall, earthquake and the rainfall and the earthquake.)

1. A model test device for simulating instability and damage of a rock-soil slope under complex conditions is characterized by comprising a wind and rain simulation system, an earthquake simulation system, a similar model test system and a monitoring system;

the wind and rain simulation system comprises a fan (1), a rainfall plate (2), a water pipe (3), a filter (5), a pressure pump (6), a valve (7), a water inlet (8), a rainfall plate bracket (9) and a water-stop plate (39);

the earthquake simulation system comprises a vibration table base (10), a spring I (11), a vertical telescopic hydraulic rod (12), a vibration table (13), a support rod (14), an inclined hydraulic rod (15), a vibration table frame (19), a horizontal telescopic hydraulic rod (20), a spring II (21), a sliding groove I (22) and a sliding rod (54);

the similar model test system comprises a test model frame (17), a side slope model (18), a load loading device (24), a water catchment structure (25) and a water-sand separation device; the water-sand separation device comprises a metal frame (34) and a screen (35);

the monitoring system comprises a displacement sensor (26), a pore water pressure sensor (27), a stress sensor (28), a water content sensor (29), an optical cable (30), a data acquisition unit (31) and a high-speed photographic camera (32);

one end of the pipeline (3) is a water inlet (8), a valve (7), a pressure pump (6) and a filter (5) are sequentially arranged on the pipeline (3) from the water inlet (8), the other end of the pipeline (3) is connected with the rainfall plate (2), the rainfall plate (2) is fixed through 4 rainfall plate supports (9), the rainfall plate (2) is a hollow plate, a plurality of rainfall holes (36) are formed in the bottom surface of the hollow plate, strip-shaped holes are formed in the side surface of the hollow plate close to the bottom surface, and the water-stop plate (39) is inserted into the hollow plate from the strip-shaped holes; the bottom surface of the rainfall plate (2) is opposite to a side slope model (18), the side slope model (18) is arranged in a test model frame (17), the test model frame (17) is a rectangular frame with an unsealed upper surface and an open side surface, more than one fan (1) is arranged on each side surface of the rectangular frame without the open side surface, the open side surface of the rectangular frame is connected with an inclined water collecting channel (25), the high end of the water collecting channel (25) is connected with the test model frame (17), the low end of the water collecting channel (25) is connected with a metal frame (34), and a screen (35) is arranged in the metal frame (34);

a load loading device (24) is arranged on the side slope model (18);

2 support rods (14) and 2 inclined hydraulic rods (15) are arranged below a model frame bottom plate (16) at the bottom of a test model frame (17), the 2 support rods (14) are parallel and close to the unsealed side of the side surface of the test model frame (17), the 2 inclined hydraulic rods (15) are parallel and far away from the unsealed side of the side surface of the test model frame (17), the bottoms of the 2 support rods (14) and the 2 inclined hydraulic rods (15) are arranged on a vibration table (13), the vibration table (13) is positioned in the middle of the vibration table frame (19), one of the two symmetrical sides of the vibration table (13) is connected with the vibration table frame (19) through two horizontal telescopic hydraulic rods (20), the other side of the two symmetrical sides of the vibration table (13) is connected with two springs II (21), the connection mode of the two left and right symmetrical sides of the vibration table (13) and the vibration table frame (19) is the same as the connection mode of the two symmetrical sides of the front and the back and the, a sliding groove I (22) is formed in one side, where a horizontal telescopic hydraulic rod (20) is located, in the vibrating table frame (19), and the horizontal telescopic hydraulic rod (20) slides along the sliding groove I (22);

the middle of the bottom of a vibration table (13) is fixedly provided with a sliding block (53), a vertical telescopic hydraulic rod (12) is arranged below the sliding block (53), the sliding block (53) and the vertical telescopic hydraulic rod (12) are not fixedly connected, the bottom of the vibration table (13) is also provided with more than two springs I (11), the more than two springs I (11) are uniformly arranged around the vertical telescopic hydraulic rod (12), the vertical telescopic hydraulic rod (12) and the more than two springs I (11) are fixedly arranged on a vibration table base (10), four corners of a vibration table frame (19) are respectively provided with a slide hole, the top of a slide rod (54) penetrates through the slide hole, and the bottom of the slide rod (54) is fixedly arranged on the vibration table base (10);

a displacement sensor (26), a pore water pressure sensor (27), a stress sensor (28) and a water content sensor (29) are arranged in a soil body of the side slope model (18), the displacement sensor (26), the pore water pressure sensor (27), the stress sensor (28) and the water content sensor (29) are connected with a data acquisition unit (31) through optical cables (30), and a high-speed camera (32) is opposite to the soil body in the side slope model (18).

2. The device for simulating the model test of the instability and destruction of the rock-soil slope under the complex conditions as claimed in claim 1, wherein the high-speed photographic camera (32) is arranged on a truss II (50) of the camera support frame (33), and the camera support frame (33) is connected with the support frame base (48) through a corner piece (49).

3. The device for simulating the model test of the instability and destruction of the rock-soil slope under the complex conditions is characterized in that the load loading device (24) comprises a telescopic hydraulic rod (40), a truss I (41), a lifting rod (42), a screw hole (43), wedge pieces (44), a plurality of rigid metal sheets (46) and electric hinges (47); connect through electronic hinge (47) between rigidity sheetmetal (46), rigidity sheetmetal (46) are connected with flexible hydraulic stem (40) top, and flexible hydraulic stem (40) bottom mounting is on truss I (41), and truss I (41) both ends are equipped with lifter (42), and lifter (42) bottom is equipped with wedge piece (44), and it has II (45) of spout to open on experimental model frame (17) frame, and II (45) of spout slide are followed in wedge piece (44).

4. The device for simulating the model test of the instability and destruction of the rock-soil slope under the complex condition according to claim 3, wherein internal threads are arranged inside two ends of the truss I (41), the lifting rod (42) is vertically provided with a plurality of screw holes (43), and the truss I (41) is connected with the lifting rod (42) through bolts.

5. The model test device for simulating the instability and destruction of the geotechnical slope under the complex condition as claimed in claim 1, wherein four connecting pieces (37) are arranged around the rainfall plate (2), one end of each connecting piece (37) is fixed at the bottom of the rainfall plate (2) through a screw (38), and the other end of each connecting piece (37) is arranged on the rainfall plate bracket (9).

6. The device for simulating the model test of the instability and destruction of the rock-soil slope under the complex condition according to claim 1, further comprising a flowmeter (4), wherein the flowmeter (4) is arranged on the pipeline (3).

7. The model test device for simulating the instability and destruction of the rock-soil slope under the complex conditions as claimed in claim 1, wherein an electric heating plate (23) is arranged in the model frame bottom plate (16) of the test model frame (17).

8. The device for simulating the model test of the instability and destruction of the rock-soil slope under the complex condition according to claim 1, further comprising a computer, wherein the vertical telescopic hydraulic rod (12), the inclined hydraulic rod (15), the horizontal telescopic hydraulic rod (20) and the telescopic hydraulic rod (40) are respectively connected with the computer.

9. The device for simulating the model test of the instability and destruction of the rock-soil slope under the complex conditions as claimed in claim 1, wherein each surface of the test model frame (17) is an acrylic plate.

Technical Field

The invention relates to a model test device for simulating instability and damage of a rock-soil slope under complex conditions, and belongs to the technical field of slope engineering and mine geotechnical engineering.

Background

Because the rock-soil body side slope has various failure mechanisms and the failure process is often accompanied with dynamic changes of various factors, the failure mechanism and the failure process are analyzed by only adopting a theoretical analysis method, the true situation of the rock-soil body side slope can not be accurately and comprehensively reflected by the obtained conclusion, in addition, the destructiveness of the engineering rock-soil body side slope is huge, and repeated experiments can not be carried out at all in reality, so that the model experiment becomes an effective way for researching the rock-soil body side slope failure mechanism and the influence degree and prevention and control measures after failure. The model is used for simulating the damage of the rock-soil body slope, so that single factors or multiple factors can be selected, parameters of the model are modified, repeated experiments under the condition of changing the single factors or the multiple factors are carried out, and obtained results can be compared and are more real and reliable.

The indoor model test is widely applied as an important engineering science research means, can effectively utilize limited manpower, material resources and time to carry out simulation research on actual projects such as slopes, reveals and reflects the essence of the phenomenon through the model test, and summarizes the conclusion rule theory to solve the actual problem. Therefore, the model test can easily process the more complex problems in the actual process and can well exert the control advantages of people, thereby being convenient for the comparative study of the test, scientific researchers in many countries of the world adopt the model test to obtain quite a lot of achievements in the fields of hydraulics, thermodynamics, aerospace, mineral engineering and the like successively, the similarity principle is the theoretical basis of the model test, the model test is actually served, and the similarity principle is met in order to accurately reflect the actual original form. The similarity theory has three related theoretical components, similar to the first theorem: the model test is similar to two physical systems of actual engineering, and a related variable equation keeps a fixed proportion (constant); similar second theorem (simulation theorem): the dimensionless proportion of the model test and the actual engineering, the length dimension, the stress dimension and the like of the model test must have the same proportion factor as the proportion of the model and the actual engineering; the third similar theorem is also called pi theorem, and according to the third similar theorem, the general requirements of model tests on geometric similarity, motion similarity, dynamic similarity, initial condition and boundary condition similarity can be summarized.

Geometric similarity means that the model is similar to the prototype in geometric shape in dimension and length, including length, area, volume scale, and subscripts M and N represent the prototype and model, respectively, such that:

length scale:

area scale:

volume scale:

the motion is similar: the velocity field of the model is similar to that of the flow field of the prototype, and the corresponding velocity V of the two flow fields is similar to the acceleration a in value and in the same direction.

Speed V scale:

acceleration a scale:

the power is similar: the prototype being proportional to the homonymous forces experienced at the corresponding points of the model stack

Force scale:

the gravity similarity criterion (the Froude criterion), when the gravity works on the power criterion, namely the Froude criterion,

rainfall and earthquake are used as main inducers of geological disasters in actual slope engineering, and the influence of the rainfall and the earthquake on the slope needs to be considered comprehensively when the slope stability is researched and analyzed. The invention provides a novel experimental device capable of effectively simulating rainfall infiltration and earthquake coupling effect on the stability of an open-air rock-soil body slope, which can not meet the current scientific research requirements.

Disclosure of Invention

Aiming at the problems and the defects in the prior art, the invention provides a model test device for simulating the instability and damage of the rock-soil side slope under the complex condition, the device can be used for carrying out an indoor side slope model test, respectively researching the dynamic evolution process of the side slope damage of the rock-soil body under the coupling action of rainfall, earthquake and the rainfall and the earthquake, and providing technical support for analyzing the stability of various engineering side slopes and natural side slopes.

A model test device for simulating instability and damage of a rock-soil slope under complex conditions comprises a wind and rain simulation system, an earthquake simulation system, a similar model test system and a monitoring system;

the wind and rain simulation system comprises a fan 1, a rainfall plate 2, a water pipe 3, a filter 5, a pressure pump 6, a valve 7, a water inlet 8, a rainfall plate bracket 9 and a water-stop plate 39;

the earthquake simulation system comprises a vibration table base 10, a spring I11, a vertical telescopic hydraulic rod 12, a vibration table 13, a support rod 14, an inclined hydraulic rod 15, a vibration table frame 19, a horizontal telescopic hydraulic rod 20, a spring II 21, a sliding groove I22 and a sliding rod 54;

the similar model test system comprises a test model frame 17, a slope model 18, a load loading device 24, a catchment structure 25 and a water-sand separation device; the water-sand separation device comprises a metal frame 34 and a screen 35;

the monitoring system comprises a displacement sensor 26, a pore water pressure sensor 27, a stress sensor 28, a water content sensor 29, an optical cable 30, a data collector 31 and a high-speed photographic camera 32;

one end of the pipeline 3 is a water inlet 8, a valve 7, a pressure pump 6 and a filter 5 are sequentially arranged on the pipeline 3 from the water inlet 8, the other end of the pipeline 3 is connected with the rainfall plate 2, the rainfall plate 2 is fixed through 4 rainfall plate supports 9, the rainfall plate 2 is a hollow plate, a plurality of rainfall holes 36 are formed in the bottom surface of the hollow plate, strip-shaped holes are formed in the side surface of the hollow plate close to the bottom surface, and the water-stop plate 39 is inserted into the hollow plate from the strip-shaped holes; the bottom surface of the rainfall plate 2 is opposite to the side slope model 18, the side slope model 18 is arranged in the test model frame 17, the test model frame 17 is a rectangular frame which is not sealed and has an opening on one side, more than one fan 1 is arranged on each side of the rectangular frame which is not opened, the side of the rectangular frame which is opened is connected with the inclined water collecting channel 25, one end of the water collecting channel 25 which is higher is connected with the test model frame 17, one end of the water collecting channel 25 which is lower is connected with the metal frame 34, and the metal frame 34 is internally provided with a screen 35;

a load loading device 24 is arranged on the side slope model 18;

2 supporting rods 14 and 2 inclined hydraulic rods 15 are arranged below a model frame bottom plate 16 at the bottom of a test model frame 17, the 2 supporting rods 14 are parallel and close to the unsealed side of the side surface of the test model frame 17 and are mainly used for supporting, the 2 inclined hydraulic rods 15 are parallel and far away from the unsealed side of the side surface of the test model frame 17, one side of the test model frame 17 can be moved up and down while supporting, and the terrain gradient is adjusted; the bottoms of 2 support rods 14 and 2 inclined hydraulic rods 15 are arranged on a vibration table 13, the vibration table 13 is positioned in the middle of a vibration table frame 19, one of two symmetrical sides of the vibration table 13 is connected with the vibration table frame 19 through two horizontal telescopic hydraulic rods 20 and used for providing horizontal vibration force, the other side of the vibration table is connected through two springs II 21 and used for compression and stretching, the connection mode of the two symmetrical sides of the vibration table 13 and the vibration table frame 19 is the same as that of the two symmetrical sides of the vibration table frame 19, namely 4 springs and 4 horizontal telescopic hydraulic rods are arranged between the vibration table 13 and the vibration table frame 19, and the two springs and the two horizontal telescopic hydraulic rods are symmetrically arranged in a group; a sliding groove I22 is formed in one side, where a horizontal telescopic hydraulic rod 20 is located, of the vibrating table frame 19, and the horizontal telescopic hydraulic rod 20 slides along the sliding groove I22 but cannot be separated from the sliding groove I22;

the middle of the bottom of the vibration table 13 is fixedly provided with a slide block 53, the slide block 53 can be bonded or welded at the bottom of the vibration table 13, a vertical telescopic hydraulic rod 12 is arranged below the slide block 53, the slide block 53 is not fixedly connected with the vertical telescopic hydraulic rod 12, the top end of the vertical telescopic hydraulic rod 12 can slide along the bottom surface of the slide block 53, the bottom of the vibration table 13 is also provided with more than two springs I11, the more than two springs I11 are uniformly arranged around the vertical telescopic hydraulic rod 12, the vertical telescopic hydraulic rod 12 and the more than two springs I11 are fixedly arranged on the vibration table base 10, four corners of a vibration table frame 19 are respectively provided with a slide hole, the top of a slide rod 54 passes through the slide hole, the bottom of the slide rod 54 is fixedly arranged on the vibration table base 10, and the vibration table frame 19, but will not be separated from the sliding rod 54, and the vibration table frame 19 will not generate horizontal displacement when the vibration table 13 vibrates horizontally;

the displacement sensor 26, the pore water pressure sensor 27, the stress sensor 28 and the water content sensor 29 are arranged in the soil body of the side slope model 18, the displacement sensor 26, the pore water pressure sensor 27, the stress sensor 28 and the water content sensor 29 are connected with the data acquisition unit 31 through the optical cable 30, and the high-speed camera 32 is opposite to the soil body in the side slope model 18 and used for shooting the change condition of the soil body.

The high-speed photographic camera 32 is arranged on a truss II 50 of the camera support frame 33, and the camera support frame 33 is connected with the support frame base 48 through a corner piece 49.

The load loading device 24 comprises a telescopic hydraulic rod 40, a truss I41, a lifting rod 42, a screw hole 43, a wedge piece 44, a plurality of rigid metal sheets 46 and an electric hinge 47; rigidity sheetmetal 46 is connected through electronic hinge 47 between, and rigidity sheetmetal 46 is connected with flexible hydraulic stem 40 top, and flexible hydraulic stem 40 bottom mounting is on truss I41, and truss I41 both ends are equipped with lifter 42, and the lifter 42 bottom is equipped with wedge piece 44, and it has II 45 of spout to open on the experimental model frame 17 frame, and wedge piece 44 slides along 45 II of spout.

Internal threads are arranged inside two ends of the truss I41, a plurality of screw holes 43 are vertically formed in the lifting rod 42, and the truss I41 is connected with the lifting rod 42 through bolts.

Four connecting pieces 37 are arranged around the rainfall plate 2, one end of each connecting piece 37 is fixed at the bottom of the rainfall plate 2 through a screw 38, and the other end of each connecting piece 37 is arranged on the rainfall plate support 9.

The pipeline 3 is also provided with a flowmeter 4 for measuring the water flow in the pipeline 3.

An electric heating plate 23 is arranged in the model frame bottom plate 16 of the test model frame 17, and can heat the interior of the test model frame 17.

The device also comprises a computer, wherein the vertical telescopic hydraulic rod 12, the inclined hydraulic rod 15, the horizontal telescopic hydraulic rod 20 and the telescopic hydraulic rod 40 are respectively connected with the computer.

Each panel of the test model frame 17 is an acrylic plate.

The pipeline 3 is connected by a right-angle joint 51 at a corner, a four-way joint 52 is arranged at the tail end of the pipeline 3 and is connected with three branch pipelines, and the three branch pipelines are distributed on the rainfall plate 2.

The working principle of the model test device for simulating the instability and damage of the rock-soil slope under the complex condition is as follows:

(1) stacking a soil sample taken on a side slope site in a test model frame 17 according to a similar principle to form a side slope model 18, embedding a displacement sensor 26, a pore water pressure sensor 27, a stress sensor 28 and a water content sensor 29 in soil of the side slope model 18 in the stacking process, connecting the soil with a data collector 31, and installing a high-speed camera 32 right opposite to the side slope model 18 to capture the appearance change of the side slope model 18 in the whole test process; adjusting the height of the inclined hydraulic rod 15 to change the inclination angle of the test model frame 17, so as to form the terrain gradient required by the test;

(2) opening a valve 7, a booster pump 6 and a filter 5, enabling water to enter the pipeline 3, pass through a flowmeter 4, enter the rainfall plate 2, draw out a water stop sheet 39 in the rainfall plate 2, and control the booster pump 6 to control the water flow in the pipeline 3 and read through the flowmeter 4; simulating rainfall to the soil body of the slope model 18 in the test model frame 17;

(3) monitoring the internal condition of the soil body through a displacement sensor 26, a pore water pressure sensor 27, a stress sensor 28 and a water content sensor 29; the slope condition in the rainfall process is shot through the high-speed camera 32;

starting a fan 1 to control gears to simulate the slope condition when the air with different strengths flows down to rain;

starting an earthquake simulation system to simulate the condition of a side slope under the action of longitudinal waves and transverse waves in the earthquake process, and simulating the condition of the side slope under different vibration frequencies by adjusting the vibration frequencies of the horizontal telescopic hydraulic rod 12 and the telescopic hydraulic rod 20;

applying loads to the upper side of the slope platform in the slope model 18 at different positions by adjusting the load loading device 24, and simulating the slope condition when the loads are distributed in different areas;

during the test, water flow and silt flow generated by the side slope flow through the water collection structure 25 flow into the water-sand separation device, water and silt are separated by the screen 35, and after the test is finished, soil samples in the test model frame 17 can be dried by the electric heating plate 23 and the fan 1 so as to carry out the next group of tests more quickly.

The invention has the beneficial effects that:

(1) the device can be used for carrying out similar model tests of various rock-soil slopes such as a refuse dump, a tailing pond, a highway or water conservancy and the like in a laboratory, researching and analyzing the dynamic evolution process of slope instability, and has the advantages of simple structure and convenient operation;

(2) the device can respectively simulate two main causes of rainfall and earthquake which occur natural geological disasters, and can effectively analyze the stability of the side slope under the coupling action of the rainfall and the earthquake or the rainfall and the earthquake;

(3) the device can effectively simulate seismic waves in the earthquake and can respectively study the stability of the slope under the coupling action of longitudinal waves, transverse waves or the longitudinal waves and the transverse waves;

(4) the rainfall plate in the device has a certain thickness, a water storage tank is formed in the rainfall plate, the rainfall holes are uniformly distributed, the water pressure of the bottom plane of the rainfall plate is consistent, and the uniform distribution of water drops can be effectively controlled; the rainfall in regions along the slope inclination can be simulated by moving the water-stop sheet;

(5) the load loading device in the device can simulate the actual situation that a certain step platform of the side slope has uniform load distribution; the displacement sensor, the pore water pressure sensor, the stress sensor and the water content sensor of the embedded model can accurately measure the displacement, the pore water pressure value, the stress value and the water content of the slope soil body in real time.

Drawings

FIG. 1 is a schematic view of the structure of an apparatus according to example 1 of the present invention;

FIG. 2 is a front view of the structure of a seismic modeling system according to embodiment 1 of the present invention;

FIG. 3 is a top view of the seismic modeling system according to embodiment 1 of the present invention;

FIG. 4 is a schematic view of the bottom structure of the rain-making plate according to embodiment 1 of the present invention;

FIG. 5 is an enlarged view of the position of the load applying means in accordance with embodiment 1 of the present invention;

fig. 6 is a schematic structural view of a load loading device according to embodiment 1 of the present invention;

in the figure: 1-a fan, 2-a rainfall plate, 3-a water pipe, 4-a flowmeter, 5-a filter, 6-a pressure pump, 7-a valve, 8-a water inlet, 9-a rainfall plate bracket, 10-a vibration table base, 11-a spring I, 12-a vertical telescopic hydraulic rod, 13-a vibration table, 14-a support rod, 15-an inclined hydraulic rod, 16-a model frame bottom plate, 17-a test model frame, 18-a slope model, 19-a vibration table frame, 20-a horizontal telescopic hydraulic rod, 21-a spring II, 22-a chute I, 23-an electric heating plate, 24-a load loading device, 25-a water gathering channel, 26-a displacement sensor, 27-a water pressure pore force sensor and 28-a stress sensor, 29-water content sensor, 30-optical cable, 31-data collector, 32-high-speed camera, 33-camera support frame, 34-metal frame, 35-screen, 36-rainfall hole, 37-connecting piece, 38-screw, 39-water stop plate, 40-telescopic hydraulic rod, 41-truss I, 42-lifting rod, 43-screw hole, 44-wedge piece, 45-chute II, 46-rigid metal sheet, 47-electric hinge, 48-support frame base, 49-corner piece, 50-truss II, 51-right-angle joint, 52-four-way joint, 53-sliding block and 54-sliding rod.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "lateral", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.