阅读说明：本技术 一种一维向土体水热迁移测试装置及其测试方法 (One-dimensional soil body hydrothermal migration testing device and testing method thereof ) 是由 刘成 仇涛 殷孝天 张敬宇 吕伟华 刘鹏 于 2020-07-05 设计创作，主要内容包括：本发明公开了一种一维向土体水热迁移测试装置及其测试方法,该装置包括传热测试阶段装置和土样切片阶段装置,所述传热测试阶段装置由土筒、试验土、温度传感器、加热板、透水石、多孔底板、盖板等组成；所述土样切片阶段装置由土筒、试验土、顶土器、切土器等组成；本发明可以开展土体一维向水热迁移规律的试验测定,能够对不同含水率的土样进行局部加热试验,切样测试并观察距加热面不同距离位置处的温度及含水率状况,分析一维向的水热迁移规律；可用于模拟盾构机掘进过程中金属刀盘结泥饼后因摩擦生热产生高温,影响开挖面土体性质而加速泥饼生成,为解决刀盘结泥饼这一常见工程难题,获得盾构泥饼的形成机理和发展规律提供一种测试手段。(The invention discloses a one-dimensional soil body hydrothermal migration testing device and a testing method thereof, wherein the device comprises a heat transfer testing stage device and a soil sample slicing stage device, wherein the heat transfer testing stage device comprises a soil cylinder, test soil, a temperature sensor, a heating plate, a permeable stone, a porous bottom plate, a cover plate and the like; the soil sample slicing stage device comprises a soil cylinder, test soil, a soil jacking device, a soil cutting device and the like; the invention can carry out test determination of the one-dimensional hydrothermal migration rule of the soil body, can carry out local heating test on soil samples with different water contents, cut the samples, test and observe the temperature and the water content conditions at different distances from a heating surface, and analyze the one-dimensional hydrothermal migration rule; the method can be used for simulating that high temperature is generated due to friction heating after the mud cake is formed on the metal cutter head in the tunneling process of the shield tunneling machine, the property of the soil body of the excavation surface is influenced, and the generation of the mud cake is accelerated, so that the common engineering problem that the mud cake is formed on the cutter head is solved, and a test means is provided for obtaining the formation mechanism and the development rule of the shield mud cake.)

1. A one-dimensional soil body hydrothermal migration testing arrangement which characterized in that: the device consists of a heat transfer testing stage device and a soil sample slicing stage device;

the heat transfer testing stage device comprises a soil cylinder (1), testing soil (2), a temperature sensor (3), a heating plate (4), a permeable stone (5), a porous bottom plate (6), a cover plate (7), screws (8) and the like;

the soil sample slicing stage device comprises a soil cylinder (1), test soil (2), a soil jacking device (9), a soil cutting device (10) and the like.

2. The heat transfer test stage device according to claim 1, wherein the soil barrel (1) is fixed with a porous bottom plate (6) at the leftmost end by a screw (8), the right side of the bottom plate is tightly attached to the permeable stone (5), and the cover plate (7) at the rightmost end is fixed by the screw (8) to form a soil box;

the soil box is filled with test soil (2), the test soil (2) is tightly attached to the heating plate (4), and temperature sensors (3) are embedded in the test soil (2) at intervals;

the inner wall of the soil cylinder (1) is provided with a layer of heat-insulating layer (11), and the edges of the upper end and the lower end are provided with partial protruding blocks;

the surface of the porous bottom plate (6) is provided with a plurality of small holes.

3. The soil sample slicing stage device according to claim 1, wherein a hook (13) of the soil ejector (9) is hooked at the end edge of the soil barrel (1), a middle push disc (16) of the soil ejector (9) pushes the test soil (2), a soil cutter (10) is erected at one side where the test soil (2) is pushed out, and a geowire saw (20) cuts a soil column of the test soil (2) along a slot of a U-shaped frame (18) of the soil cutter (10);

the middle part of the soil ejector (9) is provided with a threaded sleeve (12), a hook (13) extends out of the threaded sleeve (12) along the edge, the threaded sleeve (12) is sleeved on a threaded rod (14), the left end of the threaded rod (14) is provided with an enlarged end on the right side of a hand wheel (15), the enlarged end is nested in the center of a push disc (16), and the enlarged end and the push disc are kept to rotate relatively through a contact ball (17);

the soil cutter (10) is a U-shaped frame with a slot on the side surface, the bottom of the frame is a base (21), and the frame body of the soil cutter (10) is provided with a measuring scale (19) which can be drawn for measuring the thickness of the cut soil;

the saw frame of the geotechnical steel wire saw (20) is a U-shaped steel frame, a thin steel wire (24) is bound at the front end, the tightness degree of the steel wire (24) is adjusted through a side hand-screwed screw (23), and handles (22) are arranged on two sides of the rear end.

4. A one-dimensional soil body hydrothermal migration test method is characterized in that the test is carried out by adopting the one-dimensional soil body hydrothermal migration test device of any one of claims 1 to 3;

the heat transfer test phase method comprises the following steps:

step 1: mounting and fixing a porous bottom plate (6) by a screw (8), vertically placing the soil cylinder (1) on which the bottom plate is mounted, placing a permeable stone (5), cutting a piece of filter paper with the same section size as the permeable stone (5), placing the filter paper in the soil cylinder (1) to be attached to the permeable stone (5), and smearing a layer of vaseline on the inner wall of the soil cylinder (1);

step 2: filling prepared test soil (2) layer by layer, burying a temperature sensor (3) into the test soil (2) according to a preset distance in the soil filling process, and tamping the temperature sensor to the opening of the soil cylinder (1);

and step 3: troweling the soil surface of the opening of the soil cylinder (1), tightly attaching the heating plate (4) to the test soil (2), covering the cover plate (7) and fixing by screws (8), and horizontally placing the combined device;

and 4, step 4: the power supply of the heating plate (4) and the acquisition device of the temperature sensor (3) are switched on, and the working condition of the device is checked;

and 5: setting the heating temperature of the heating plate (4), starting a test, and collecting the temperature values of the sensors at various distances;

step 6: when the heating time is up, the power supply and the temperature sensor (3) of the heating plate (4) are closed, and the next stage, namely the soil sample slicing stage, is started;

the soil sample slicing stage method comprises the following steps:

step 1: the porous bottom plate (6) and the cover plate (7) are removed, and the permeable stone (5), the filter paper and the heating plate (4) are taken out;

step 2: placing the soil pushing device (9) on the left side of the soil barrel (1) filled with the test soil (2), hooking the hook (13) on the protruding block at the left end of the soil barrel (1), and rotating the hand wheel (15) to enable the push disc (16) to be tightly attached to the test soil (2);

and step 3: placing the soil cutter (10) on the right side of the soil cylinder (1) filled with the test soil (2), adjusting a measuring ruler (19) to determine the soil cutting thickness each time, and clamping a steel wire (24) of the earth engineering wire saw (20) in a slot opening of a U-shaped frame (18) of the soil cutter (10);

and 4, step 4: slowly rotating the hand wheel (15) to push out the test soil (2) from the left side to the right side of the soil cylinder (1);

and 5: observing a measuring scale (19) on the soil cutter (10), and cutting an earth worker wire saw (20) when the test soil (2) pushes out the earth pillar with the specified thickness, and neatly slicing the earth pillar;

step 6: and (3) classifying and numbering the cut samples of the test soil (2), weighing and drying the samples, and calculating the change condition of the water content of the soil layers with different thicknesses from the heating surface.

Technical Field

The invention belongs to the technical field of geotechnical engineering model tests, and particularly relates to a one-dimensional hydrothermal migration testing device and a testing method for geotechnical model soil.

Background

The clay debris cut by the shield cutter head when the shield cutter head passes through the clay stratum can be adhered to the surface of the cutter head, solid or semisolid blocks are formed under the extrusion action of the cutter head and are adhered to and block the cutter head, so that the penetration of a cutter is reduced when the stratum is cut, the shield excavation efficiency is reduced, and the adhesion of soil and the surface of the cutter head is one of important reasons for generating mud cakes on the surface of the cutter head. The existence of mud cake not only can lead to the increase of shield structure blade disc moment of torsion, still can block up the thick liquid mouth of inhaling of arranging the thick liquid pipe, will seriously influence shield structure construction technique and construction safety, and the processing and the restoration of a series of construction problems such as dregs improvement, mud cake are clear away, shield structure system transformation, shut down the operation of opening the cabin, risk are taken precautions against, greatly increased construction cost.

Under the normal working condition, the temperature of the shield cutter head is generally 40-50 ℃, but in the tunneling process of the shield, particularly under the condition of a composite stratum, the torque and the total thrust of the cutter head are greatly increased and the propelling speed is reduced along with the formation and the increase of mud cakes, so that the temperature of the cutter head is as high as 400-500 ℃ and even higher.

Researches show that the water content and the temperature of the soil body have great influence on the adhesion characteristics of the soil body and an interface, so that the formation mechanism and the development rule of the shield mud cake are required to be obtained, the common engineering problem that a cutter head is stuck with the mud cake is solved, the property of the soil body of an excavation surface influenced by the high temperature of the cutter head is required to be known, and the research on the hydrothermal migration rule of the soil body in a heating state is necessary. The invention can provide a casing pipe type soil body one-dimensional hydrothermal migration testing device and a testing method, and provides a testing means for solving the rule of influence of temperature on soil body properties.

Disclosure of Invention

In order to research the change rule of water and temperature in the soil body in the heating state of the soil body, the invention provides a model test sleeve type one-dimensional hydrothermal migration test device and a test method for the soil body.

The technical scheme adopted by the invention is as follows:

a one-dimensional soil body hydrothermal migration testing arrangement which characterized in that: the device comprises a heat transfer testing stage device and a soil sample slicing stage device; the heat transfer testing stage device comprises a soil cylinder, test soil, a temperature sensor, a heating plate, a permeable stone, a porous bottom plate, a cover plate, screws and the like; the soil sample slicing stage device comprises a soil cylinder, test soil, a soil jacking device, a soil cutting device and the like.

The heat transfer test stage device is characterized in that the leftmost end of the soil barrel is fixed with a porous bottom plate through screws, the right side of the bottom plate is tightly attached to the permeable stone, and the rightmost end of the soil barrel is fixed with a cover plate through screws to form a soil box; the soil box is filled with test soil, the test soil is tightly attached to the heating plate, and one temperature sensor is embedded in the test soil at intervals; the inner wall of the soil cylinder is provided with a layer of heat-insulating layer, and the edges of the upper end and the lower end of the soil cylinder are provided with partial protruding blocks; the surface of the porous bottom plate is provided with a plurality of small holes.

The soil sample slicing stage device is characterized in that a hook of the soil ejector is hooked at the edge of the end part of a soil cylinder, a push disc in the middle of the soil ejector pushes test soil, a soil cutter is erected on one side, from which the test soil is pushed out, a geodetic wire saw cuts a test soil column along a U-shaped frame slot opening of the soil cutter, and the ejector can keep the pushed test soil column complete and cannot be broken or damaged along with disturbance; the middle part of the soil ejector is provided with a threaded sleeve, a hook extends out of the edge of the threaded sleeve, the threaded sleeve is sleeved on a threaded rod, the left end of the threaded rod is provided with a hand wheel, the right side of the hand wheel is an amplifying end, the amplifying end is embedded in the center of a push disc, and the relative rotation between the amplifying end and the push disc is kept through a contact ball; the soil cutting device is a U-shaped frame with a slot on the side surface, the bottom of the frame is an amplifying base, the soil cutting device frame body is provided with a measuring scale which can be drawn and used for measuring the thickness of cut soil, the soil cutting device measuring scale can accurately measure the thickness of cut soil, and the guide groove ensures the regularity of cut surfaces. The geotechnical steel wire saw frame is a U-shaped steel frame, a thin steel wire is bound at the front end, the tightness degree of the steel wire is adjusted through a side hand-screwed screw, handles are arranged on two sides of the rear end to apply force when soil is conveniently cut, the geotechnical steel wire saw is used for slicing soil samples, the geotechnical steel wire saw is simple and convenient to operate, the manual non-uniformity that the steel wire saw is directly used for cutting soil under the conventional operation is replaced, and the accuracy of the distance between each layer of soil samples is improved.

A one-dimensional soil body hydrothermal migration testing method is characterized by comprising a heat transfer testing stage method and a soil sample slicing stage method.

The heat transfer test phase comprises the following steps:

(1) installing and fixing a porous bottom plate by screws, vertically placing the soil cylinder with the bottom plate installed, placing permeable stones, cutting a piece of filter paper with the same section size as the permeable stones, placing the filter paper in the soil cylinder to be attached to the permeable stones, and smearing a layer of vaseline on the inner wall of the soil cylinder;

(2) filling prepared test soil in layers, burying a temperature sensor into the test soil according to a preset test distance in the soil filling process, and tamping the temperature sensor to a soil barrel opening;

(3) leveling the soil surface of the soil barrel opening, tightly attaching a heating plate to the test soil, covering a cover plate and fixing by screws, and horizontally placing the combined device;

(4) switching on a heating plate power supply and a temperature sensor acquisition device, and checking the working condition of the device;

(5) setting heating temperature of a heating plate, starting a test, and collecting sensor temperature values at various distances;

(6) and when the heating time is up, the power supply of the heating plate and the temperature sensor are closed, and the next stage, namely the soil sample slicing stage, is started.

The soil sample slicing stage comprises the following steps:

(1) removing the porous bottom plate and the cover plate, and taking out the permeable stone, the filter paper and the heating plate;

(2) placing the soil pushing device on the left side of the soil barrel filled with test soil, enabling the hook to be hooked on the protruding block at the left end of the soil barrel, and rotating the hand wheel to enable the push disc to be tightly attached to the test soil;

(3) placing the soil cutter on the right side of the soil cylinder filled with test soil, adjusting a measuring tape to determine the soil cutting thickness each time, and clamping a steel wire of the geotechnical wire saw in a slot opening of a U-shaped frame of the soil cutter;

(4) slowly rotating the hand wheel to push out the test soil from the left side to the right side of the soil cylinder;

(5) observing a measuring scale on the soil cutter, cutting an earth worker wire saw when the test soil pushes out the soil column with the specified thickness, and regularly slicing the soil column;

(6) and (4) carrying out classification numbering on the cut test soil samples, weighing, drying, and calculating the change condition of the water content of the soil layers with different thicknesses from the heating surface.

Advantageous effects

The invention can carry out test and determination of the one-dimensional hydrothermal migration rule of the soil body, can be used for simulating that high temperature is generated due to friction heating after the mud cake is formed on the metal cutter head in the tunneling process of the shield tunneling machine, and the soil body property of the excavation surface is influenced, so that the generation of the mud cake is accelerated, and provides a test means for solving the common engineering problem of the mud cake formed on the cutter head and obtaining the formation mechanism and the development rule of the shield mud cake.

Description of the drawings:

FIG. 1 is a structural diagram of a heat transfer test stage of a one-dimensional soil body hydrothermal migration test device provided by the invention;

FIG. 2 is a structural diagram of a soil sample slicing stage device of the one-dimensional soil body hydrothermal migration testing device provided by the invention;

FIG. 3 is a cross-sectional view of the perforated base plate of FIG. 1;

FIG. 4 is a cross-sectional view of a portion of the cover of FIG. 1;

FIG. 5 is a left side view of the soil sample slicing stage apparatus of FIG. 2;

FIG. 6 is a right side view of the soil sample slicing stage apparatus of FIG. 2;

FIG. 7 is a view of the configuration of the earth mover of FIG. 2;

FIG. 8 is a view of the construction of the soil cutter of FIG. 2;

FIG. 9 is a right side view of the earth cutter of FIG. 2;

in the attached figures 1-9

The soil testing device comprises a soil cylinder 1, test soil 2, a temperature sensor 3, a heating plate 4, a permeable stone 5, a porous bottom plate 6, a cover plate 7, a screw 8, a soil jacking device 9, a soil cutting device 10, a heat insulation layer 11, a threaded sleeve 12, a hook 13, a threaded rod 14, a hand wheel 15, a push disc 16, a ball 17, a U-shaped frame 18, a measuring scale 19, a geotechnical steel wire saw 20, a base 21, a handle 22, a hand-screwed screw 23 and a steel wire 24.

The specific implementation mode is as follows:

in order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.

As shown in fig. 1 to 9, a casing pipe type one-dimensional hydrothermal migration testing device and method are characterized in that: the device consists of a heat transfer testing stage device and a soil sample slicing stage device, and the method consists of a heat transfer testing stage and a soil sample slicing stage; the heat transfer testing stage device comprises a soil cylinder 1, test soil 2, a temperature sensor 3, a heating plate 4, a permeable stone 5, a porous bottom plate 6, a cover plate 7, screws 8 and the like; the soil sample slicing stage device comprises a soil cylinder 1, test soil 2, a soil jacking device 9, a soil cutting device 10 and the like.

The leftmost end of the soil cylinder 1 is fixed with a porous bottom plate 6 by a screw 8, the right side of the bottom plate is tightly attached to a permeable stone 5, and the rightmost end is fixed with a cover plate 7 by the screw 8 to form a soil box; the soil box is filled with test soil 2, the test soil 2 is tightly attached to the heating plate 4, and sensors are embedded in the test soil 2 at intervals; the soil type, the water content compactness and other parameters of the test soil 2 are determined according to test requirements, and the test soil is filled into a soil box in a layering mode and tamped; the size of the heating plate 4 is determined according to the simulation proportion of the test, and the heating power and the temperature can be controlled according to the heating temperature requirement of the test; the sensor can be one of a temperature sensor 3, a soil moisture sensor or a multifunctional sensor; the inner wall of the soil cylinder 1 is provided with a layer of heat-insulating layer 11, the edges of the upper end and the lower end are provided with partial protruding blocks for a hook 13 of a soil jacking device 9, and the protruding blocks can be one of hollow cylinders or hollow prisms and are made of metal or engineering plastics; the surface of the porous bottom plate 6 is provided with a plurality of small holes, and in a hydrothermal migration test, the bottom porous bottom plate 6 is the only penetrating surface due to the fact that the wall of the soil barrel 1 is sealed, and one-dimensional hydrothermal migration is achieved.

The hook 13 of the soil ejector 9 is hooked at the end edge of the soil barrel 1, the middle push disc 16 of the soil ejector 9 pushes the test soil 2, the soil cutter 10 is erected on one side, from which the test soil 2 is pushed out, the earth moving saw 20 cuts the soil column of the test soil 2 along the slot opening of the U-shaped frame 18 of the soil cutter 10, and the ejector can ensure that the pushed-out soil column of the test soil 2 is complete and cannot be broken or damaged along with disturbance; the middle part of the soil ejector 9 is provided with a threaded sleeve 12, a hook 13 extends out of the edge of the threaded sleeve 12, the threaded sleeve 12 is sleeved on a threaded rod 14, the left end of the threaded rod 14 is provided with a hand wheel 15, the right side of the hand wheel 15 is an enlarged end, the enlarged end is nested in the center of a push disc 16, and the relative rotation between the enlarged end and the push disc is kept through a contact ball 17; the soil cutting device 10 is a U-shaped frame with a slot on the side surface, the bottom of the frame is an amplifying base 21, and the frame body of the soil cutting device 10 is provided with a measuring scale 19 which can be drawn for measuring the thickness of the cut soil. The cutting frame of the geotechnical wire saw 20 is a U-shaped steel frame, a thin steel wire 24 is bound at the front end, the tightness degree of the steel wire 24 is adjusted through a side hand screw 238, handles 22 are arranged on two sides of the rear end to apply force when soil is conveniently cut, the soil cutting thickness is accurately measured by the soil cutting device measuring ruler 19, the slit opening ensures the cutting surface regularity, the geotechnical wire saw 20 is used for cutting soil samples, the operation is simple and convenient, the manual non-uniformity of directly cutting soil by the wire saw under the conventional operation is replaced, and the accuracy of the distance between each layer of soil samples is greatly improved.