Vacuum combined heating foundation drainage test instrumentTechnical field
The invention belongs to build work test apparatus technical field, and in particular to a kind of vacuum combined heating foundation drainage experimentInstrument.
Background technology
The outstanding feature of new hydraulic reclamation ultra-soft soil is that surface strength is extremely low, and its basement process is problem generally acknowledged both at home and abroad.It is rightThis kind of ground is typically reinforced using draining concretion method, and preloading, vacuum method or vacuum are mainly used in ChinaCombined heap load precompacting method.But use conventional draining concretion method to reinforce stream mud, the mud scum of new hydraulic reclamation, it is pre- by 3~5 monthsPressure is reinforced, and settlement of foundation often exceeds that the settling amount of theoretical calculation is many than more significant, but the increased number of intensity after reinforcingValue is smaller, it is impossible to meets the requirement of ground.
To ground vacuumize while combine ground heating, be a kind of new foundation drainage reinforcement means, purport of the present inventionA kind of vacuum combined heating foundation drainage test instrument is being provided, model engineering is put into practice under lab by this test instrument, is helpedTesting crew effective evaluation foundation drainage effect, and key parameter is studied.
The content of the invention
It is an object of the invention to overcome the deficiencies of the prior art and provide a kind of vacuum combined heating foundation drainage experimentInstrument.
The present invention is achieved by the following technical solutions：
A kind of vacuum combined heating foundation drainage test instrument, including soil sample chamber outer wall, upper cover plate, lower bottom base and dress of weighingPut；
The soil sample chamber outer wall is the steel cylinder of both ends open, and soil sample chamber outer wall lower port is placed on the annular recessed of lower bottom baseOn in groove, soil sample chamber outer wall upper port is placed in the annular groove of upper cover plate, and upper cover plate and lower bottom base pass through screw rod, nut groupSoil sample chamber outer wall is stepped up to fix by part, and the space between soil sample chamber outer wall, upper cover plate and lower bottom base forms soil sample chamber；
At least a heating rod, heating rod bottom are provided with soil sample chamber to be fixedly mounted on lower bottom base vertically, are heatedRod electrically connects with the heating controller outside soil sample chamber；
An at least vacuum-pumping tube connected with the vavuum pump outside soil sample chamber is provided with soil sample chamber；
The temperature sensor for detecting soil sample temperature is provided with soil sample chamber；
The baroceptor for detecting absolute pressure is provided with vacuum-pumping tube；
Lower bottom base is placed on weighing device, is lost using the water quality of the soil sample in weighing device measurement soil sample chamber.
In the above-mentioned technical solutions, in order to ensure the sealing of soil sample chamber, in the annular groove of upper cover plate and lower bottom baseAnnular groove in be provided with sealing rubber ring.
In the above-mentioned technical solutions, vacuum-pumping tube is through being arranged on upper cover plate, and vacuum-pumping tube bottom is deeply to soil sample chamberInterior, vacuumizing in soil sample chamber uniformly offers through hole and is enclosed with filter cloth on pipeline section, and upper cover plate is stretched out in vacuum-pumping tube outlet, takes outVacuum tube outlet connects vavuum pump by flexible pipe.
In the above-mentioned technical solutions, the temperature sensor is arranged on soil sample chamber outer wall in the present embodiment, and temperature passesThe probe of sensor gos deep into soil sample chamber.
The application method of the vacuum combined heating foundation drainage test instrument is as follows：
Step 1：Upper cover plate is opened, soil sample is inserted into soil sample chamber, to loading the parameters such as soil sample height, moisture content, densityIt is measured；Then upper cover plate is installed, upper cover plate is fixed with lower bottom base with screw rod, nut assembly, makes vacuum-pumping tube insertion soilIn sample；Then the initial value of weighing device is recorded；
Step 2：Heating rod is opened, the soil sample in soil sample chamber is heated, and opens vavuum pump, utilizes vacuum-pumping tubeTo carrying out vacuumize process in soil sample chamber；
Step 3：Soil sample indoor temperature, the vacuum of record at different moments, and the value of weighing of weighing device；
Step 4：Experimental data is arranged, vacuum combined heating foundation drainage effect is evaluated according to experimental data.
Further, in step 2, matching is carried out according to the following table in heating-up temperature and absolute pressure, by the liquid in soil sampleState water is converted into gaseous state；I.e. when heating-up temperature is 50 DEG C, absolute pressure need to be less than 12.34kPa, then water switchs to gas by liquidState；When heating-up temperature is 55 DEG C, absolute pressure need to be less than 15.743kPa, then water switchs to gaseous state by liquid；When heating-up temperature isAt 60 DEG C, absolute pressure need to be less than 19.923kPa, then water switchs to gaseous state by liquid；When geotemperature is 65 DEG C, absolute pressure25.014kPa need to be less than, then water switchs to gaseous state by liquid；When heating-up temperature is 70 DEG C, absolute pressure need to be less than31.164kPa, then water gaseous state is switched to by liquid.
| Temperature (DEG C) | 50 | 55 | 60 | 65 | 70 |
| Absolute pressure (kPa) | 12.34 | 15.743 | 19.923 | 25.014 | 31.164 |
The advantages of the present invention are：
The present invention is reasonable in design, simple in construction, simulates vacuum combined heating ground row under lab by this test instrumentWater method, testing crew effective evaluation foundation drainage effect is helped, and key parameter is studied.
Using weighing device, the water quality penalty values of the soil sample in soil sample chamber during experiment can be supervised in real timeSurvey.During experiment, water can gasify, and discharge rate can not be drawn by measuring the quality of water, so this test instrument passes through titleReset the value of weighing that the initial value put subtracts weighing device during experiment, the water of the soil sample during as testing in soil sample chamberMass loss value.
Brief description of the drawings
Fig. 1 is the structural representation of the present invention.
Fig. 2 is the structural representation of the soil sample chamber outer wall of the present invention.
Fig. 3 is the upper cover plate of the present invention, the structural representation of lower bottom base.
Embodiment
Technical scheme is further illustrated with reference to specific embodiment.
A kind of vacuum combined heating foundation drainage test instrument, referring to accompanying drawing 1, including soil sample chamber outer wall 1, upper cover plate 2, bottomSeat 3 and weighing device 13；
The soil sample chamber outer wall 1 is the steel cylinder (referring to accompanying drawing 2) of both ends open, and soil sample chamber outer wall lower port is placed on downOn in the annular groove of base 3, soil sample chamber outer wall upper port is placed in the annular groove of upper cover plate 2, upper cover plate and lower bottom baseSoil sample chamber outer wall is stepped up to fix by screw rod, nut assembly 4, the space shape between soil sample chamber outer wall, upper cover plate and lower bottom baseInto soil sample chamber, in order to ensure the sealing of soil sample chamber, it is all provided with the annular groove of upper cover plate and in the annular groove of lower bottom baseIt is equipped with sealing rubber ring 5；
At least a heating rod 6, heating rod bottom is provided with soil sample chamber to be fixedly mounted on lower bottom base 3, add verticallyHot pin electrically connects with the heating controller 7 outside soil sample chamber；
At least one vacuum-pumping tube 8 connected with the vavuum pump outside soil sample chamber is provided with soil sample chamber, vacuum-pumping tube passes throughWear and be arranged on upper cover plate 2, vacuum-pumping tube bottom is goed deep into soil sample chamber, and vacuumizing in soil sample chamber uniformly offers on pipeline sectionThrough hole and filter cloth is enclosed with, upper cover plate is stretched out in vacuum-pumping tube outlet, and vacuum-pumping tube outlet connects vavuum pump 10 by flexible pipe 9；
The temperature sensor 11 for detecting soil sample temperature is provided with soil sample chamber, the temperature passes in the present embodimentSensor 11 is arranged on soil sample chamber outer wall, and the probe of temperature sensor gos deep into soil sample chamber；
The baroceptor 14 for detecting absolute pressure, the lead of baroceptor 14 are provided with vacuum-pumping tube 8Draw vacuum-pumping tube 8 and be connected to detecting instrument 15；
Lower bottom base 3 is placed on weighing device 13, and the water quality that the soil sample in soil sample chamber is measured using weighing device 13 is damagedLose.
In the present embodiment, referring to accompanying drawing 3, upper cover plate and lower bottom base are that shape is identical, symmetrically arranged two plectanes,Be provided with upper cover plate and lower bottom base position it is corresponding be used for penetrate the through hole a of screw rod, in the relative of upper cover plate and lower bottom baseFace is provided with the annular groove for installing soil sample chamber outer wall, and sealing rubber ring 5 is provided with annular groove.
The application method of vacuum combined heating foundation drainage test instrument is as follows：
Step 1：Upper cover plate 2 is opened, soil sample is inserted into soil sample chamber, to loading the ginseng such as soil sample height, moisture content, densityNumber is measured；Then upper cover plate 2 is installed, upper cover plate is fixed with lower bottom base with screw rod, nut assembly, inserts vacuum-pumping tubeIn soil sample；Then the initial value of weighing device is recorded；
Step 2：Heating rod 6 is opened, the soil sample in soil sample chamber is heated, and open vavuum pump 10, using vacuumizingPipe is to carrying out vacuumize process in soil sample chamber；
Step 3：Soil sample indoor temperature, the vacuum of record at different moments, and the value of weighing of weighing device；
Step 4：Arranging experimental data, (initial value of weighing device subtracts the value of weighing of weighing device during experiment, i.e.,During experiment, the water quality penalty values of the soil sample in soil sample chamber), according to experimental data to vacuum combined heating foundation drainageEffect is evaluated.
In step 2, in step 2, heating-up temperature and absolute pressure are matched according to following table (table 1), by soilAqueous water in sample is converted into gaseous state；I.e. when heating-up temperature is 50 DEG C, absolute pressure need to be less than 12.34kPa, then water is by liquidSwitch to gaseous state；When heating-up temperature is 55 DEG C, absolute pressure need to be less than 15.743kPa, then water switchs to gaseous state by liquid；Work as heatingWhen temperature is 60 DEG C, absolute pressure need to be less than 19.923kPa, then water switchs to gaseous state by liquid；When geotemperature is 65 DEG C, absolutely25.014kPa need to be less than to pressure, then water switchs to gaseous state by liquid；When heating-up temperature is 70 DEG C, absolute pressure need to be less than31.164kPa, then water gaseous state is switched to by liquid.
| Temperature (DEG C) | 50 | 55 | 60 | 65 | 70 |
| Absolute pressure (kPa) | 12.34 | 15.743 | 19.923 | 25.014 | 31.164 |
Table 1
Exemplary description has been done to the present invention above, it should explanation, in the situation for the core for not departing from the present inventionUnder, any simple deformation, modification or other skilled in the art can not spend the equivalent substitution of creative work equalFall into protection scope of the present invention.