CN109612904B - Device and method for acquiring response characteristics of excess pore water pressure and fracture water pressure - Google Patents
Device and method for acquiring response characteristics of excess pore water pressure and fracture water pressure Download PDFInfo
- Publication number
- CN109612904B CN109612904B CN201811506224.4A CN201811506224A CN109612904B CN 109612904 B CN109612904 B CN 109612904B CN 201811506224 A CN201811506224 A CN 201811506224A CN 109612904 B CN109612904 B CN 109612904B
- Authority
- CN
- China
- Prior art keywords
- model
- water
- water pressure
- fracture
- response characteristics
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/082—Investigating permeability by forcing a fluid through a sample
- G01N15/0826—Investigating permeability by forcing a fluid through a sample and measuring fluid flow rate, i.e. permeation rate or pressure change
Abstract
The invention discloses a device and a method for acquiring response characteristics of excess pore water pressure and fracture water pressure, and the device comprises a model box and a model arranged in the model box, wherein the top of the model box is provided with a sealing cover, the rear part of the model box is provided with a water tank, one side of the water tank, which is in contact with the model box, is provided with a permeable stone baffle, the bottom of the model box is provided with a vibrating table, the vibrating table is placed in a hanging basket of a centrifugal machine, and the model is internally provided with a water content sensor and a pore pressure sensor. According to the invention, a centrifuge vibration table test is carried out on the model, and the response characteristics of the pore water pressure and the fracture water pressure of the slope weak layer zone in the centrifugal vibration process, the deformation characteristics of the model and the crack dilatation characteristics of the slope weak layer zone in the vibration process are analyzed. Providing scientific basis for the excitation effect of the pore water and the fracture water of the large landslide in the earthquake.
Description
Technical Field
The invention relates to the technical field of centrifuge shaking tables, in particular to a device and a method for acquiring response characteristics of ultra-pore water pressure and fracture water pressure.
Background
The two global earthquake zones in China, namely the clamping areas of the Mediterranean-Himalayashan earthquake zone and the Pacific earthquake zone, are one of the areas with the most concentrated and highest activity of global continental earthquakes, the very prominent earthquake-induced landslide geological disaster problem occurs in history and current earthquake activities, particularly the MS8.0 level earthquake in Wenchuan in Sichuan in 2008, landslide events which are recorded so far and are generated by single earthquake and have the densest distribution, the most quantity and the widest area are generated, and the landslide events with great economic loss and casualties are caused.
The weak zone is a discontinuous geological interface with small thickness, obviously lower mechanical strength than upper and lower surrounding rocks, filled with weak substances such as chyle prism, cobble, cracked rock and the like. In the strong earthquake process, the water guide weak zone below the underground water level of the slope is subjected to the instantaneous impact compression action of the overlying strata, so that the water in the zone is not discharged in time, the obvious instantaneous high pore water pressure is generated, the shear strength of the weak zone is suddenly reduced, and the landslide is suddenly started. Due to the complex field environment conditions and the fact that the weak zone is deeply buried under the earth surface, the pore pressure response of the weak zone is difficult to obtain through field monitoring.
Disclosure of Invention
Aiming at the defects in the prior art, the device and the method for acquiring response characteristics of the excess pore water pressure and the fracture water pressure under the vibration condition solve the problem that the pore pressure response of the earthquake weak layer is difficult to acquire through on-site monitoring.
In order to achieve the purpose of the invention, the invention adopts the technical scheme that: the device is characterized by comprising a model box and a model arranged in the model box, wherein a sealing cover is arranged at the top of the model box, a water tank is arranged at the rear part of the model box, a permeable stone baffle is arranged on one side of the water tank, which is in contact with the model box, the bottom of the model box is a vibrating table, the vibrating table is placed in a hanging basket of a centrifugal machine, and a water content sensor and a pore pressure sensor are arranged in the model.
Further: the model is a slope model comprising a lower hard layer, a soft layer belt and a lower hard layer, wherein the soft layer belt is a soft layer belt with high water permeability.
Further: electrodes are embedded at two ends of the soft layer belt.
The beneficial effect of adopting the further scheme is as follows: the resistivity in the zone is measured in real time in the centrifugal vibration process of the model by a motor and a quadrupole method, the resistivity can change due to fracture compression and expansion, volume expansion and groundwater entry, and the underground water content, volume expansion and rock mass damage characteristics of the weak zone can be indirectly reflected through the resistivity change.
Further: and a water level sensor is arranged in the water tank.
The beneficial effect of adopting the further scheme is as follows: the water level sensor can detect the water level in the water tank in real time.
Further: the side surface of the model box is made of toughened glass.
The beneficial effect of adopting the further scheme is as follows: and observing the deformation condition of the model from the side through the toughened glass on the side surface of the model box.
A method for obtaining response characteristics of excess pore water pressure and fracture water pressure comprises the following steps:
s1, building a model in the model box, curing and molding the model, detecting the moisture content in the model through a moisture content sensor in the model, and stopping curing when the moisture content is reduced to 5%;
s2, filling water into the model box to submerge the model, detecting the water content in the model through a water content sensor, and discharging the water in the model box when the water content reaches the saturated water content;
s3, coating underwater cementing agents on the two sides of the model, and forming waterproof layers on the two side walls of the model to prevent water in the model from flowing out of the two side walls;
s4, placing the model box on a vibration table of a centrifuge, and enabling the centrifuge to apply a centrifugal force of 15g and stably run for 2 min;
s5, filling water into the water tank, replenishing underground water to the model through the water tank, and then applying a centrifugal force of 150g to the centrifugal force to stably run until water seeps from the front part of the model;
and S6, increasing the acceleration of the centrifuge to a preset value, stably running, simultaneously opening the vibration table, measuring the pore pressure and the fracture water pressure through the pore pressure sensor, and measuring the resistivity of the soft and weak zone through the electrode.
Further: the configuration method of the model comprises the following steps:
firstly, a lower hard layer is poured on the inner foot of a model box, after the lower hard layer is poured, a soft interlayer is poured after the lower hard layer is subjected to shaving treatment, and after the soft interlayer is poured, an upper hard layer is poured after the soft interlayer is subjected to shaving treatment.
Further: the upper hard layer and the lower hard layer are made of the same raw materials, and the mass ratio of the upper hard layer to the lower hard layer is as follows:
barite powder: 40-mesh quartz sand: nano cement: iron powder: water: glycerin ═ 37.5: 37.5: 7: 18: 11.48: 2.3;
the mass ratio of the soft interlayer is as follows:
80 parts of aggregate and 20 parts of cementing agent by weight; the aggregate comprises: 60-mesh quartz sand: 100-mesh quartz sand: 200-mesh quartz sand: bentonite 40: 44: 13: 3;
the underwater cementing agent is 0.8-1.5wt% of organic salt high molecular polymer solution, and the organic salt high molecular polymer solution comprises 3-7 wt% of hydroxyethyl cellulose aqueous solution, 1-3 wt% of sodium polyacrylate aqueous solution and 1-3 wt% of polyethylene glycol aqueous solution.
The invention has the beneficial effects that: according to the invention, a centrifuge vibration table test is carried out on the model, and the response characteristics of the pore water pressure and the fracture water pressure of the slope weak layer zone in the centrifugal vibration process, the deformation characteristics of the model and the crack dilatation characteristics of the slope weak layer zone in the vibration process are analyzed. Providing scientific basis for the excitation effect of the pore water and the fracture water of the large landslide in the earthquake.
Drawings
FIG. 1 is a block diagram of the present invention.
The method specifically comprises the following steps: 1. a model box; 2. a model; 21. a lower hard layer; 22. a weak layer band; 23. an upper hard layer; 3. a water tank; 4. a permeable stone baffle; 5. a vibration table 6, a centrifuge; 7. a sealing cover; 8. and an electrode.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
As shown in figure 1, the device for acquiring the response characteristics of the excess pore water pressure and the fracture water pressure comprises a model box 1 and a model 2 arranged in the model box 1, wherein a sealing cover 7 is arranged at the top of the model box 1, a water tank 3 is arranged at the rear part of the model box 1, a permeable stone baffle 4 is arranged on one side, in contact with the model box 1, of the water tank 3, a vibrating table 5 is arranged at the bottom of the model box 1, the vibrating table 5 is placed in a hanging basket 6 of a centrifugal machine, and a water content sensor and a pore pressure sensor are arranged in the model 2.
In one embodiment of the invention, the model 2 is a ramp model comprising a lower hard layer 21, a weak layer strip 22 and a lower hard layer 23, said weak layer strip 22 being a high water permeable weak layer strip. Electrodes are embedded at two ends of the soft layer belt. The resistivity in the zone is measured in real time in the centrifugal vibration process of the model by using a quadrupole method, the resistivity can change due to fracture compression and expansion, volume expansion and underground water entering, and the underground water content, volume expansion and material damage characteristics of the weak zone can be indirectly reflected through the resistivity change.
In one embodiment of the present invention, a water level sensor is provided in the water tank 3, and the water level sensor can detect the water level in the water tank in real time.
In one embodiment of the invention, the side surface of the mold box 1 is made of toughened glass, and the deformation of the mold is observed from the side surface through the toughened glass on the side surface of the mold box.
An experimental method for obtaining response characteristics of excess pore water pressure and fracture water pressure comprises the following steps:
and S1, building a model in the model box, curing and molding the model, detecting the moisture content in the model through a moisture content sensor in the model, and stopping curing when the moisture content is reduced to 5%.
The configuration method of the model comprises the following steps:
firstly, a lower hard layer is poured on the inner foot of a model box, after the lower hard layer is poured, a soft interlayer is poured after the lower hard layer is subjected to shaving treatment, and after the soft interlayer is poured, an upper hard layer is poured after the soft interlayer is subjected to shaving treatment.
The upper hard layer and the lower hard layer are made of the same raw materials, and the mass ratio of the upper hard layer to the lower hard layer is as follows:
barite powder: 40-mesh quartz sand: nano cement: iron powder: water: glycerin ═ 37.5: 37.5: 7: 18: 11.48: 2.3;
the mass ratio of the soft interlayer is as follows:
80 parts of aggregate and 20 parts of cementing agent by weight; the aggregate comprises: 60-mesh quartz sand: 100-mesh quartz sand: 200-mesh quartz sand: bentonite 40: 44: 13: 3;
the underwater cementing agent is 0.8-1.5wt% of organic salt high molecular polymer solution, and the organic salt high molecular polymer solution comprises 3-7 wt% of hydroxyethyl cellulose aqueous solution, 1-3 wt% of sodium polyacrylate aqueous solution and 1-3 wt% of polyethylene glycol aqueous solution.
And S2, filling water into the model box to submerge the model, detecting the water content in the model through a water content sensor, and discharging the water in the model box when the water content reaches the saturated water content. When the water content is about 20%, the model is considered to be saturated. The lid may be saturated with vacuum, which may result in faster and more efficient saturation.
And S3, coating the two sides of the model with an underwater cementing agent to form waterproof layers on the two side walls of the model, so as to prevent water in the model from flowing out of the two side walls. The water flows out from the front surface, and the flow direction of the underground water in the actual slope is met.
And S4, placing the model box on a vibration table of a centrifuge, and enabling the centrifuge to apply a centrifugal force of 15g and stably run for 2 min. So that the stress of the model can be adjusted, and saturated water in the model can form a certain flowing trend.
And S5, filling water into the water tank, replenishing underground water to the model through the water tank, and applying a centrifugal force of 150g to the centrifugal force to stably operate until the front part of the model is infiltrated. This indicates that the water tank supplies groundwater to the model and a weak zone in the model forms stable groundwater flow.
And S6, increasing the acceleration of the centrifuge to a preset value, stably running, simultaneously opening the vibration table, measuring the pore pressure and the fracture water pressure through the pore pressure sensor, and measuring the resistivity of the soft and weak zone through the electrode.
Before the test, a modal analysis function of finite element software ANSYS is selected, a subspace method is adopted to extract a model, the inherent frequency of the slope is extracted, and the model is compared with the input frequency of the centrifuge, so that the possibility of resonance is eliminated. During the test, an input wave adopts an acceleration spectrum recorded by a Wenchuan earthquake clear platform station, horizontal and vertical synthetic excitation is applied at the same time, white noise scanning is performed in advance at the beginning stage of the test according to experience, the initial dynamic characteristic of the model is tested, white noise is applied when the excitation is finished, and the inherent period and the variation of the damping ratio of the model are tested.
Claims (6)
1. A method for obtaining response characteristics of excess pore water pressure and fracture water pressure is characterized in that the method for obtaining the response characteristics of the excess pore water pressure and the fracture water pressure is realized based on a device for obtaining the response characteristics of the excess pore water pressure and the fracture water pressure, the device comprises a model box (1) and a model (2) arranged in the model box (1), a sealing cover (7) is arranged at the top of the model box (1), a water tank (3) is arranged at the rear part of the model box (1), a permeable stone baffle (4) is arranged on one side, in contact with the model box (1), of the water tank (3), a vibrating table (5) is arranged at the bottom of the model box (1), the vibrating table (5) is placed in a hanging basket (6) of a centrifugal machine, and a water content sensor and a pore pressure sensor are arranged in the model (2);
the method for acquiring response characteristics of the excess pore water pressure and the fracture water pressure specifically comprises the following steps:
s1, building a model in the model box, curing and molding the model, detecting the moisture content in the model through a moisture content sensor in the model, and stopping curing when the moisture content is reduced to 5%;
s2, filling water into the model box to submerge the model, detecting the water content in the model through a water content sensor, and discharging the water in the model box when the water content reaches the saturated water content;
s3, coating underwater cementing agents on the two sides of the model, and forming waterproof layers on the two side walls of the model to prevent water in the model from flowing out of the two side walls;
s4, placing the model box on a vibration table of a centrifuge, and enabling the centrifuge to apply a centrifugal force of 15g and stably run for 2 min;
s5, filling water into the water tank, replenishing underground water to the model through the water tank, and then applying a centrifugal force of 150g to the centrifugal force to stably run until water seeps from the front part of the model;
s6, increasing the acceleration of the centrifuge to a preset value, stably running, simultaneously opening the vibration table, measuring the pore pressure and the fracture water pressure through the pore pressure sensor, and measuring the resistivity of the soft and weak zone through the electrode;
the configuration method of the model comprises the following steps:
firstly, a lower hard layer is poured in a model box, after the lower hard layer is poured, a soft layer belt is poured after the lower hard layer is subjected to shaving treatment, and after the soft layer belt is poured, an upper hard layer is poured after the soft layer belt is subjected to shaving treatment.
2. The method for obtaining the response characteristics of the excess pore water pressure and the fracture water pressure as claimed in claim 1, wherein the upper hard layer and the lower hard layer are made of the same raw materials, and the mass ratio of the upper hard layer to the lower hard layer is as follows:
barite powder: 40-mesh quartz sand: nano cement: iron powder: water: glycerol = 37.5: 37.5: 7: 18: 11.48: 2.3;
the soft layer belt comprises the following components in percentage by mass:
80 parts of aggregate and 20 parts of cementing agent by weight; the aggregate comprises: 60-mesh quartz sand: 100-mesh quartz sand: 200-mesh quartz sand: bentonite = 40: 44: 13: 3;
the underwater cementing agent is 0.8-1.5wt% of organic salt high molecular polymer solution, and the organic salt high molecular polymer solution comprises 3-7 wt% of hydroxyethyl cellulose aqueous solution, 1-3 wt% of sodium polyacrylate aqueous solution and 1-3 wt% of polyethylene glycol aqueous solution.
3. The method for obtaining the response characteristics of the excess pore water pressure and the fracture water pressure as claimed in claim 1, wherein the model (2) is a slope model comprising a lower hard layer (21), a weak layer band (22) and an upper hard layer (23), and the weak layer band (22) is a weak layer band with high water permeability.
4. The method for obtaining the response characteristics of the excess pore water pressure and the fracture water pressure as claimed in claim 3, wherein the electrodes (8) are embedded at both ends of the weak layer band (22).
5. The method for obtaining response characteristics of excess pore water pressure and fracture water pressure as claimed in claim 1, wherein a water level sensor is arranged in the water tank (3).
6. The method for obtaining the response characteristics of the excess pore water pressure and the fracture water pressure as claimed in claim 1, wherein the side surface of the model box (1) is made of tempered glass.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811506224.4A CN109612904B (en) | 2018-12-10 | 2018-12-10 | Device and method for acquiring response characteristics of excess pore water pressure and fracture water pressure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811506224.4A CN109612904B (en) | 2018-12-10 | 2018-12-10 | Device and method for acquiring response characteristics of excess pore water pressure and fracture water pressure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109612904A CN109612904A (en) | 2019-04-12 |
| CN109612904B true CN109612904B (en) | 2021-07-06 |
Family
ID=66006963
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811506224.4A Active CN109612904B (en) | 2018-12-10 | 2018-12-10 | Device and method for acquiring response characteristics of excess pore water pressure and fracture water pressure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109612904B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110243413B (en) * | 2019-06-27 | 2021-04-16 | 浙江大学 | Monitoring device and monitoring method for physical state of supergravity centrifugal model |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102494957A (en) * | 2011-11-22 | 2012-06-13 | 浙江大学 | Layered shear model box for centrifuge shaking table test |
| CN101833894B (en) * | 2010-04-16 | 2012-09-19 | 中国科学院武汉岩土力学研究所 | Preparation method of earthquake landslide vibrating table test physical model |
| CN104359638A (en) * | 2014-10-21 | 2015-02-18 | 中国电建集团成都勘测设计研究院有限公司 | Overweight force field vibration-table loading device |
| CN208013212U (en) * | 2017-03-16 | 2018-10-26 | 水利部交通运输部国家能源局南京水利科学研究院 | A kind of super gravity field shaketalle test adds discharge mechanism |
-
2018
- 2018-12-10 CN CN201811506224.4A patent/CN109612904B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101833894B (en) * | 2010-04-16 | 2012-09-19 | 中国科学院武汉岩土力学研究所 | Preparation method of earthquake landslide vibrating table test physical model |
| CN102494957A (en) * | 2011-11-22 | 2012-06-13 | 浙江大学 | Layered shear model box for centrifuge shaking table test |
| CN104359638A (en) * | 2014-10-21 | 2015-02-18 | 中国电建集团成都勘测设计研究院有限公司 | Overweight force field vibration-table loading device |
| CN208013212U (en) * | 2017-03-16 | 2018-10-26 | 水利部交通运输部国家能源局南京水利科学研究院 | A kind of super gravity field shaketalle test adds discharge mechanism |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109612904A (en) | 2019-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Porcino et al. | Static and dynamic properties of a lightly cemented silicate-grouted sand | |
| Vilar et al. | Collapse behavior of soil in a Brazilian region affected by a rising water table | |
| CN106198137B (en) | A kind of three axis sample making apparatus of unimolecule high polymer stockpile and application method | |
| CN109612904B (en) | Device and method for acquiring response characteristics of excess pore water pressure and fracture water pressure | |
| CN106644336B (en) | A kind of frame structure crosses over ground fissure experimental system and method | |
| Hsiao et al. | Evaluation of static and dynamic properties of sand–fines mixtures through the state and equivalent state parameters | |
| Li et al. | Experimental study on the vertical deformation of sand caused by cyclic withdrawal and recharging of groundwater | |
| Kumar et al. | Centrifuge testing to investigate effects of partial saturation on the response of shallow foundation in liquefiable ground under strong sequential ground motions | |
| CN109211652B (en) | A method of it prepares containing monitoring property microfissure seepage flow test specimen | |
| JP2009236716A (en) | Manufacturing method of sample of foundation improvement construction method test | |
| JP2010196464A (en) | Construction method for countermeasure against liquefaction of sandy ground | |
| Shahsavari et al. | Cemented paste backfill consolidation with deposition-dependent boundary conditions | |
| Choo et al. | Seepage behavior of drainage zoning in a concrete faced gravel-fill dam via centrifuge and numerical modeling | |
| CN102901691A (en) | Method for testing compaction coefficient of dry concrete | |
| JP2011157804A (en) | Sand ground improvement method and apparatus used for the same | |
| Joseph et al. | Laboratory evaluation of extent of smear zone due to columnar intrusion for cochin marine clays | |
| SHI et al. | Preliminary study on real-time pore water pressure response and reinforcement mechanism of air-booster vacuum preloading treated dredged slurry | |
| Takemura et al. | Centrifuge model tests on soil desaturation as a liquefaction countermeasure | |
| EP3445915B1 (en) | Method and kit for mitigating the risk of liquefaction of ground to be consolidated | |
| Galeandro et al. | Infiltration processes in fractured and swelling soils and their influence on the stability of surficial covers | |
| Wang et al. | Dynamic modelling for feasibility study of the shallow CO2 injection experiment at the CO2CRC Otway site, Victoria, Australia | |
| CN205276238U (en) | Normal position detection device based on collapsible loess | |
| CN109580304B (en) | The shake table model preparation method of pore pressure response is driven for water weak intercalated layer of satisfying | |
| Isobe et al. | Study on long-term subsidence of soft clay due to 2007 Niigata Prefecture Chuetsu-Oki Earthquake | |
| Zakaria et al. | Effect of vibration load on leaching process for sandy gypseous soil |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |