CN111595723A - In-situ testing method for density of soil containing massive stones - Google Patents
In-situ testing method for density of soil containing massive stones Download PDFInfo
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- CN111595723A CN111595723A CN202010668516.9A CN202010668516A CN111595723A CN 111595723 A CN111595723 A CN 111595723A CN 202010668516 A CN202010668516 A CN 202010668516A CN 111595723 A CN111595723 A CN 111595723A
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- air bag
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
- G01N9/02—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by measuring weight of a known volume
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
- G01N9/02—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by measuring weight of a known volume
- G01N2009/022—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by measuring weight of a known volume of solids
- G01N2009/024—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by measuring weight of a known volume of solids the volume being determined directly, e.g. by size of container
Abstract
The invention provides a method for testing the density of a large-block stone-containing soil in situ, which comprises the following implementation processes: selecting a representative leveling field, excavating to remove a loose soil layer on the surface, determining the diameter and depth of a test pit according to the maximum particle size of a soil sample, excavating the test pit, and weighing the quality of the excavated soil sample; the elastic air bag is placed in the test pit, and the volume of the test pit (namely the in-situ volume of the soil sample) is calculated by means of the accumulation of the amount of gas substances when the volume rigid air bag inflates the elastic air bag for multiple times and the method of replacing the volume of the test pit with the volume of the elastic air bag, so as to calculate the density of the soil sample. Based on the state equation of ideal gas, the invention measures the volume of the test pit by means of a method of repeatedly inflating the elastic air bag by the volume rigid air bag, and further calculates the density of the soil sample containing the massive rock soil; when the maximum particle size of the soil sample is large, the method has the advantages of no need of a sand source and a water source, portability of a measuring device, simplicity and convenience in test and easiness in implementation.
Description
Technical Field
The invention relates to a method for testing the density of the soil containing massive stones in situ, belongs to the technical field of geotechnical tests, and particularly relates to a method for testing the density of the soil containing massive stones in situ based on an ideal gas state equation.
Background
The mountainous regions in the western region of China are widely distributed, along with the development of national economy, the continuous promotion of urbanization, and the 'mountain opening and land building' become an important means for obtaining flat land in the western region of China. Aiming at the western mountainous area, a large amount of boulders can be formed in the excavation process, and the boulders are used as filling materials of filling engineering, so that the filling engineering is economical and convenient.
In the filling process, the soil density is always an important index for evaluating the soil reinforcing effect, and the existing in-situ density testing method mainly comprises a cutting ring method, a sand pouring method and a water pouring method. Wherein the ring cutting method is suitable for fine soil. Aiming at the soil containing massive stones, the maximum grain size of a soil sample is larger than 0.2m, sometimes the maximum grain size can reach 0.5m, and in order to ensure that the density test result is not influenced by the particle distribution, the soil sample is representative, and the diameter and the depth of a soil sampling test pit are about 2 m. If the traditional sand irrigation method and irrigation method are used, sand or water with the volume exceeding 6 cubic meters needs to be weighed, the weighing from the raw materials is difficult, and the method is more difficult to implement particularly for areas far away from sand sources and water sources.
Disclosure of Invention
In order to solve the technical problems, the invention provides an in-situ test method for the density of the soil containing the massive gravels, which solves the problem that the existing in-situ density test method is difficult to implement when aiming at the density test of the soil containing the massive gravels.
The invention is realized by the following technical scheme.
The invention provides a method for testing the density of soil containing massive stones in situ, which comprises the following steps:
firstly, preparing a rigid air bag and an elastic air bag, and selecting a site needing to dig a test pit;
leveling the field, removing a loose soil layer on the surface of the field needing excavation of the test pit, and determining the diameter and the depth of the test pit needing excavation;
thirdly, acquiring a test pit according to the determined diameter and depth of the test pit, taking out all loosened soil samples, and weighing the mass m of the soil samples;
fourthly, inflating the rigid air bag, and recording the air pressure and the temperature at the moment;
fifthly, placing the elastic air bag into the test pit, and pressing all the gas in the rigid air bag into the elastic air bag;
sixthly, covering a rigid flat plate on the elastic air bag, and recording the air pressure and the temperature at the moment;
seventhly, calculating the density of the soil sample;
a first inflation and exhaust pipe is arranged on the rigid air bag, and a first thermometer and a first barometer are sequentially arranged on one side of the first inflation and exhaust pipe; the elastic air bag is internally inserted with a second thermometer and a second barometer, a second inflation and exhaust pipe is arranged at the edge of the elastic air bag, one end of the second inflation and exhaust pipe is communicated with the elastic air bag, and the other end of the second inflation and exhaust pipe is provided with an air pipe connecting port.
In the step I, a 2m multiplied by 2m flat field is selected.
In the second step, the diameter and the depth of the test pit are respectively determined according to 4 times and 5 times of the maximum particle size of the large rock soil.
And in the third step, excavating and sampling according to the determined diameter and depth of the test pit, excavating the bottom surface of the test pit into a pot bottom shape, and weighing the mass m of the soil sample containing the large stone.
The pit bottom is in a smooth arc shape, and the surface of the pit is not provided with protrusions or depressions.
In step ④, the rigid air bag is inflated to fully inflate the rigid air bag, and the reading P of the first barometer at the moment is recordediFirst thermometer reading Ti(K) And i is the inflation frequency, wherein the first inflation i is 1, the second inflation i is 2, and the first inflation i is l.
In the fifth step, the elastic air bag is placed in the test pit, the first inflation exhaust pipe and the second inflation exhaust pipe are communicated, all the air in the rigid air bag is pressed into the elastic air bag, and the second air stop valve is closed.
The step of sixthly comprises the following steps:
(6.1) repeating the fourth step and the fifth step until the elastic air bag wall is jointed with the test pit wall, the bottom of the elastic air bag is jointed with the bottom of the test pit, and the top of the elastic air bag is higher than the ground level of the test pit field;
(6.2) covering a rigid flat plate with the size of 2m multiplied by 2m on the surface of the rigid air bag, applying pressure to the rigid plate to enable the rigid plate to be fully attached to the flat ground, and recording the reading P of the second barometer and the reading T (K) of the second thermometer at the moment.
In the step (c), the pit volume V and the density ρ of the soil sample containing large stone blocks are calculated by using the following calculation formula:
wherein V is the volume of the test pit, T is the temperature in the elastic air bag, and V0Is the volume of the rigid air bag, P is the air pressure in the elastic air bag, l is the total inflation times of the rigid air bag, PiFor the pressure in the rigid bladder at the i-th inflation, TiThe temperature in the rigid air bag during the ith inflation, V '' is the volume of the wall of the elastic air bag, ρ is the density of the soil sample in the test pit, and m is the mass of the soil sample in the test pit.
The invention has the beneficial effects that: based on the state equation of ideal gas, measuring the volume of the test pit by means of a method of repeatedly inflating the elastic air bag by the volume rigid air bag, and further calculating the density of the soil sample containing the massive rock soil; when the maximum particle size of the soil sample is large, the method has the advantages of no need of a sand source and a water source, portability of a measuring device, simplicity and convenience in test and easiness in implementation.
Drawings
FIG. 1 is a flow chart of the present invention;
FIG. 2 is a schematic diagram of a rigid air bag test apparatus used in the present invention;
FIG. 3 is a schematic structural diagram of an elastic air bag testing device used in the present invention;
in the figure: 1-rigid air bag, 2-first thermometer, 3-first barometer, 4-first air stop valve, 5-first inflation and exhaust pipe, 6-elastic air bag, 7-second thermometer, 8-second barometer, 9-second air stop valve, 10-second inflation and exhaust pipe and 11-air pipe connector.
Detailed Description
The technical solution of the present invention is further described below, but the scope of the claimed invention is not limited to the described.
As shown in fig. 1 to 3, a method for in-situ testing the density of a soil containing massive stones comprises the following steps:
firstly, preparing a rigid air bag and an elastic air bag, and selecting a 2m multiplied by 2m flat field;
removing loose soil layers on the surface of the test pit to be excavated, and determining the diameter and the depth of the test pit to be excavated;
excavating a test pit, taking out all loosened soil samples, and weighing the mass m of the soil samples;
fourthly, inflating the rigid air bag, and recording the air pressure and the temperature at the moment;
fifthly, placing the elastic air bag into the test pit, and pressing all the gas in the rigid air bag into the elastic air bag;
sixthly, covering a rigid flat plate on the elastic air bag, and recording the air pressure and the temperature at the moment;
seventhly, calculating the density of the soil sample;
the volume is fixed to V after being filled with air0The rigid air bag 1 is provided with a first inflation and exhaust pipe 5, and one side of the first inflation and exhaust pipe 5 is sequentially provided with a first thermometer 2 and a first barometer 3; a second thermometer 7 and a second barometer 8 are inserted in the elastic air bag 6 with the volume capable of changing along with the internal and external pressure, a second inflation and exhaust pipe 10 is arranged at the edge of the elastic air bag 6, one end of the second inflation and exhaust pipe 10 is communicated with the elastic air bag 6, and an air pipe connecting port 11 is arranged at the other end of the second inflation and exhaust pipe.
And a first air stop valve 4 is arranged on the first air inflation and exhaust pipe 5, and a second air stop valve 9 is arranged on the second air inflation and exhaust pipe 10.
The first pneumatic exhaust pipe 5 may communicate with a second pneumatic exhaust pipe 10.
The volume of the elastic balloon 6 is much larger than the volume of the rigid balloon 1.
One end of the first inflation and exhaust pipe 5 is communicated with the interior of the rigid air bag 1.
In the second step, the diameter and the depth of the test pit are respectively determined according to 4 times and 5 times of the maximum particle size of the large rock soil.
And in the third step, excavating and sampling according to the determined diameter and depth of the test pit, excavating the bottom surface of the test pit into a pot bottom shape, and weighing the mass m of the soil sample containing the large stone.
The bottom of the pit is in a smooth arc shape, and the surface of the pit is not provided with obvious protrusions or depressions.
In step ④, the rigid air bag is inflated to fully inflate the rigid air bag, and the reading P of the first barometer at the moment is recordediFirst thermometer reading Ti(K) Wherein i is the inflation frequency, the first inflation i is 1, the second inflation i is 2, … …, and the first inflation i is l.
In the fifth step, the elastic air bag is placed in the test pit, the first inflation exhaust pipe and the second inflation exhaust pipe are communicated, all the gas in the rigid air bag is pressed into the elastic air bag, and the second air stop valve is closed.
The step of sixthly comprises the following steps:
(6.1) repeating the fourth step and the fifth step until the elastic air bag wall is jointed with the test pit wall, the bottom of the elastic air bag is jointed with the bottom of the test pit, and the top of the elastic air bag is higher than the ground level of the test pit field;
(6.2) covering a rigid flat plate with the size of 2m multiplied by 2m on the surface of the elastic air bag, applying pressure to the rigid plate to enable the rigid plate to be fully attached to the flat ground, and recording the reading P of the second barometer and the reading T (K) of the second thermometer at the moment.
In the test process, the pressure intensity and the pressure of the gas in the air bag are close to normal temperature and normal pressure, the gas can be considered as ideal gas in the calculation process, and the physical quantity of the gas meets the following relationship:
rigid air bags:
PiV0＝niRTi(1)
an elastic airbag:
PV'＝nRT (2)
and the sum of the amounts of all gaseous substances in the elastic airbag and the sum of the amounts of all gaseous substances in the rigid airbag have the following relationship:
the gas volume V' in the elastic airbag after covering the rigid plate is expressed by the following formula:
wherein, PiFor the pressure, V, in the rigid bladder at the i-th inflation0Is a rigid bladder volume, TiIs the temperature in the rigid air bag during the ith inflation, R is the universal gas constant, niThe total quantity of all gas substances in the rigid air bag during the ith inflation, n is the total quantity of all gas substances in the elastic air bag after the rigid plate applies pressure, V' is the internal gas volume of the elastic air bag after the rigid plate applies pressure, P is the gas pressure in the elastic air bag, T is the temperature in the elastic air bag, and l is the total number of times of inflation of the rigid air bag.
The test pit volume may be the sum of the volume of the elastic bladder wall and the volume of gas within the elastic bladder:
the density rho of the soil sample containing the massive stone soil is as follows:
then, the in-situ test density of the soil sample can be calculated by using the following two formulas:
wherein V is the volume of the test pit,t is the temperature in the elastic airbag, V0Is the volume of the rigid air bag, P is the air pressure in the elastic air bag, l is the total inflation times of the rigid air bag, PiFor the pressure in the rigid bladder at the i-th inflation, TiThe temperature in the rigid air bag during the ith inflation, V '' is the volume of the wall of the elastic air bag, ρ is the density of the soil sample in the test pit, and m is the mass of the soil sample in the test pit.
Claims (9)
1. The in-situ test method for the density of the soil containing the massive stones is characterized by comprising the following steps: the method comprises the following steps:
firstly, preparing a rigid air bag and an elastic air bag, and selecting a site needing to dig a test pit;
leveling the field, removing a loose soil layer on the surface of the field needing excavation of the test pit, and determining the diameter and the depth of the test pit needing excavation;
excavating the field according to the determined diameter and depth of the test pit to obtain the test pit, taking out all loosened soil samples, and weighing the mass m of the soil samples;
fourthly, inflating the rigid air bag, and recording the air pressure and the temperature at the moment;
fifthly, placing the elastic air bag into the test pit, and pressing all the gas in the rigid air bag into the elastic air bag;
sixthly, covering a rigid flat plate on the elastic air bag, and recording the air pressure and the temperature at the moment;
seventhly, calculating the density of the soil sample;
a first inflation and exhaust pipe (5) is arranged on the rigid air bag (1), and a first thermometer (2) and a first barometer (3) are sequentially arranged on one side of the first inflation and exhaust pipe (5); the elastic air bag (6) is internally connected with a second thermometer (7) and a second barometer (8) in an inserting mode, a second inflation and exhaust pipe (10) is arranged on the edge of the elastic air bag (6), one end of the second inflation and exhaust pipe (10) is communicated with the elastic air bag (6), and an air pipe connecting port (11) is arranged at the other end of the second inflation and exhaust pipe.
2. The method of in situ testing of the density of the mass-containing rock soil of claim 1, wherein: in the step I, a 2m multiplied by 2m flat field is selected.
3. The method of in situ testing of the density of the mass-containing rock soil of claim 1, wherein: in the second step, the diameter and the depth of the test pit are respectively determined according to 4 times and 5 times of the maximum particle size of the large rock soil.
4. The method of in situ testing of the density of the mass-containing rock soil of claim 1, wherein: and in the third step, excavating and sampling according to the determined diameter and depth of the test pit, excavating the bottom surface of the test pit into a pot bottom shape, and weighing the mass m of the soil sample containing the large stone.
5. The method of in situ testing of the density of the mass-containing rock soil of claim 4, wherein: the pit bottom is in a smooth arc shape, and the surface of the pit is not provided with protrusions or depressions.
6. The method of claim 1, wherein the rigid bladder is inflated to inflate the rigid bladder sufficiently to record a first barometer reading P at ④iFirst thermometer reading Ti(K) And i is the inflation frequency, wherein the first inflation i is 1, the second inflation i is 2, and the first inflation i is l.
7. The method of in situ testing of the density of the mass-containing rock soil of claim 1, wherein: in the fifth step, the elastic air bag is placed in the test pit, the first inflation exhaust pipe and the second inflation exhaust pipe are communicated, all the gas in the rigid air bag is pressed into the elastic air bag, and the second air stop valve is closed.
8. The method of in situ testing of the density of the mass-containing rock soil of claim 1, wherein: the step of sixthly comprises the following steps:
(6.1) repeating the fourth step and the fifth step until the elastic air bag wall is jointed with the test pit wall, the bottom of the elastic air bag is jointed with the bottom of the test pit, and the top of the elastic air bag is higher than the ground level of the test pit field;
(6.2) covering a rigid flat plate with the size of 2m multiplied by 2m on the surface of the elastic air bag, applying pressure to the rigid plate to enable the rigid plate to be fully attached to the flat ground, and recording the reading P of the second barometer and the reading T (K) of the second thermometer at the moment.
9. The method of in situ testing of the density of the mass-containing rock soil of claim 1, wherein: in the step (c), the pit volume V and the density ρ of the soil sample containing large stone blocks are calculated by using the following calculation formula:
wherein V is the volume of the test pit, T is the temperature in the elastic air bag, and V0Is the volume of the rigid air bag, P is the air pressure in the elastic air bag, l is the total inflation times of the rigid air bag, PiFor the pressure in the rigid bladder at the i-th inflation, TiThe temperature in the rigid air bag during the ith inflation, V '' is the volume of the wall of the elastic air bag, ρ is the density of the soil sample in the test pit, and m is the mass of the soil sample in the test pit.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010668516.9A CN111595723A (en) | 2020-07-13 | 2020-07-13 | In-situ testing method for density of soil containing massive stones |
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| CN202010668516.9A CN111595723A (en) | 2020-07-13 | 2020-07-13 | In-situ testing method for density of soil containing massive stones |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111912484A (en) * | 2020-09-08 | 2020-11-10 | 东风汽车集团有限公司 | Device and method for rapidly measuring volume of automobile trunk |
| CN117233035A (en) * | 2023-11-10 | 2023-12-15 | 寿光市勘察设计院有限责任公司 | Sample density testing system for rock-soil investigation test |
-
2020
- 2020-07-13 CN CN202010668516.9A patent/CN111595723A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111912484A (en) * | 2020-09-08 | 2020-11-10 | 东风汽车集团有限公司 | Device and method for rapidly measuring volume of automobile trunk |
| CN111912484B (en) * | 2020-09-08 | 2021-05-18 | 东风汽车集团有限公司 | Device and method for rapidly measuring volume of automobile trunk |
| CN117233035A (en) * | 2023-11-10 | 2023-12-15 | 寿光市勘察设计院有限责任公司 | Sample density testing system for rock-soil investigation test |
| CN117233035B (en) * | 2023-11-10 | 2024-01-30 | 寿光市勘察设计院有限责任公司 | Sample density testing system for rock-soil investigation test |
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