CN205934996U - Combined testing device for horizontal displacement of pile top and stress of pile body of precast pile - Google Patents

Abstract

The utility model belongs to the technical field of in-situ test equipment for civil engineering, and relates to a joint test device for the horizontal displacement of the pile top and the stress of the pile body of prefabricated piles. The grating sensor demodulator is electrically connected; the engineering pile is connected to the jack through a steel plate pad, a pad is placed under the jack, the load sensor is in contact with the pressure end of the jack, and the load sensor is connected to the load sensor display; the spherical hinge support One side is in contact with the load sensor, and the other side is in contact with the test pile. The first and second bore angle steels are respectively fixed with a first dial gauge and a second dial gauge. The end of the test pile is far away from the jack. The first reference beam is supported, and the second reference beam is fixed on the side of the first reference beam far away from the jack; the structure is simple, the operation is convenient, the cost is low, the test accuracy is high, the operability is strong, and the numerical results are obtained directly and the precision is high , the error is small.

Description

A joint test device for horizontal displacement of prefabricated pile pile top and pile body stress

Technical field:

The utility model belongs to the technical field of in-situ test equipment for civil engineering, and relates to a combined test device for the horizontal displacement of the prefabricated pile top and the stress of the pile body, which makes up for and improves the shortcomings of the current test device, and can be more accurate, comprehensive and convenient. The horizontal displacement of the prefabricated pile is obtained, and the stress distribution of the pile body is obtained by embedding the FBG sensor, which provides a basis for the experimental research of the prefabricated pile and the detection of the pile foundation.

Background technique:

Prefabricated piles are widely used in the civil engineering industry. With the deepening of urban development and the continuous innovation of construction technology, more and more bridges and port projects are being constructed, and the load requirements are getting higher and higher. In such projects, the pile foundation In addition to bearing large vertical loads, foundation piles are often subjected to large horizontal loads due to wave force, wind force, vibration force, ship impact force, and braking force of vehicle loads. Under load, it is particularly important to study and detect the bearing characteristics and stress distribution of pile foundations. In the horizontal load test and detection of existing engineering piles, only the horizontal bearing capacity of the piles has been studied and detected, and because of the different construction sites, the loading devices are not the same, sometimes due to the unsatisfactory installation of the loading device, Specifications will lead to inaccurate test results or even failure, so the reasonable installation and collocation of loading devices are very important for the research and testing of the horizontal load characteristics of piles. FBG sensing technology is a new type of optoelectronics technology with the development of optical fiber communication technology and fiber optics. It has good test data stability, high precision, small size, light weight, easy laying and installation, and strong anti-interference ability. , waterproof, moisture-proof, high temperature resistance, corrosion resistance, multi-series connection and other characteristics, it is widely used in engineering fields such as settlement monitoring of bridges, tunnels and jacket offshore platforms. It is easy to fall off, and the test results are greatly affected by temperature, which will make the measurement data inaccurate and cause the test to fail. Therefore, it is of great significance for engineering research and testing to seek a new pile horizontal load test device that can test the pile body stress.

Invention content:

The purpose of the invention of this utility model is to overcome the shortcomings of the prior art, and seek to design and provide a combined test device for the horizontal displacement of the top of the prefabricated pile and the stress of the pile body. The test of the stress of the pile body is added to the horizontal load test of the prefabricated pile for direct measurement. The horizontal displacement and pile body stress of prefabricated piles are convenient for studying the horizontal load bearing capacity and mechanical characteristics of prefabricated piles.

In order to achieve the above object, the main structure of the utility model includes engineering piles, steel plate spacers, jacks, load sensors, spherical hinge supports, test piles, the first dial indicator, the first magnetic table seat, the first reference beam, the first Dial indicator, second magnetic base, second reference beam, self-compensating fiber grating strain sensor string, load sensor display device, fiber grating sensor demodulator, first drilling angle steel, spacer and second drilling angle steel The two sides of the test pile are vertically engraved with grooves with a cross-section of 5mm×5mm, and the self-compensating fiber grating strain sensor strings with dense upper and lower sparse structures are embedded in the grooves of the test pile and sealed with structural glue, self-compensating The fiber grating strain sensor string is electrically connected with the fiber grating sensor demodulator; the engineering pile provides the reaction force for the test pile, and a similar pile with a bearing capacity greater than or equal to the test pile is selected; the engineering pile is connected to the jack through the steel plate cushion block, and the steel plate cushion block The number is determined according to the distance between the test pile and the engineering pile to ensure that the engineering pile can provide sufficient reaction force; a pad is placed under the jack, and the load sensor is in contact with the pressure end of the jack to accurately measure the pressure exerted by the jack value, the load sensor is connected to the load sensor display instrument; one side of the spherical hinge support is in contact with the load sensor, and the other side is in contact with the test pile to ensure that the force applied by the jack acts on the test pile evenly; the test pile is in contact with the horizontal force center The two sides of the parallel place are fixed with the first drilled angle steel with expansion screws, and the vertical position on both sides of the test pile is 50cm above the parallel to the horizontal force center, and the second drilled angle steel is fixed in the same way. The first dial indicator and the second dial indicator are fixedly installed on the angle steel and the second drilling angle steel respectively, and the dials of the first dial indicator and the second dial indicator are parallel to the ground; A first reference beam is supported at 30cm of the pile, and the first dial indicator is connected with the first magnetic base placed on the first reference beam; a second reference beam is fixed on the side of the first reference beam away from the jack, and the second reference beam 10cm away from the first reference beam, and the height of the second reference beam is higher than the first reference beam, and the second reference beam is correspondingly placed at the same position as the first reference beam with a second magnetic gauge connected to the second dial gauge seat.

The engineering piles described in the utility model include prestressed hollow pipe piles, prestressed hollow square piles and solid square piles.

The utility model realizes the testing process of the horizontal displacement of the prefabricated pile and the stress of the pile body as follows:

(1) Before pressing the pile, carve 5mm×5mm grooves on both sides of the test pile, put the prefabricated self-compensating fiber grating strain sensor strings into the two grooves, seal them with structural glue, and maintain In two days, the string of self-compensating fiber grating strain sensors formed a structure with a dense top and a sparse bottom;

(2) When the test pile can be used normally, select a suitable engineering pile to provide a reaction force to ensure that its bearing capacity is greater than or equal to the test pile;

(3) Place spherical hinge bearings, load sensors, jacks, and steel plate cushions in sequence between the test pile and the engineering pile. The number of steel plate cushions is determined according to the distance between the test pile and the engineering pile to ensure that the engineering pile can Fully provide the reaction force, place the block under the jack to ensure that the centroid of the jack coincides with the center of each part of the test device, and the center of each part of the test device is perpendicular to the embedded self-compensating fiber grating strain sensor string;

(4) Use a drilling rig to drill two holes on both sides of the test pile parallel to the center of the horizontal force, and fix the drilled angle steel with expansion screws. drilling angle steel;

(5) Support the first benchmark beam at the end of the test pile far away from the jack 30cm away from the test pile and place the first magnetic gauge base on the first benchmark beam, fix the first dial indicator on the first drilled angle steel, the first The dial of the dial indicator is parallel to the ground; fix the second benchmark beam on the side away from the jack, the distance between the second benchmark beam and the first benchmark beam is 10cm, and ensure that the second benchmark beam is higher than the first benchmark beam, and the second benchmark beam Put the second magnetic watch base on the beam, fix the second dial indicator on the second drilled angle steel, and the dial of the second dial indicator is parallel to the ground;

(6) Connect the self-compensating FBG strain sensor string with the FBG sensor demodulator, and connect the load sensor with the load sensor display device;

(7) After checking that the components of the test device are installed correctly, carry out a load test on the test pile, record the corresponding displacement and stress change values, and complete the test of the horizontal displacement and pile body stress of the prefabricated pile.

Compared with the existing test device, the utility model has the advantages of simple structure, convenient operation, low cost, high test precision, strong operability, direct numerical results, high precision and small error.

Description of drawings:

Fig. 1 is the principle diagram of the main structure of the utility model.

Fig. 2 is a schematic diagram of installation of the self-compensating fiber grating strain sensor string of the present invention.

Fig. 3 is a schematic diagram of the contact between the jack and the steel plate spacer of the present invention.

Fig. 4 is a schematic diagram of the arrangement of the reference beam of the present invention.

detailed description:

Below by embodiment and in conjunction with accompanying drawing, the utility model is further described.

Example:

The main structure of this embodiment includes engineering pile 1, steel plate cushion block 2, jack 3, load sensor 4, spherical hinge support 5, test pile 6, first dial indicator 7, first magnetic table base 8, first reference Beam 9, second dial gauge 10, second magnetic base 11, second reference beam 12, self-compensating fiber grating strain sensor string 13, load sensor display 14, fiber grating sensor demodulator 15, first drilling Angle steel 16, cushion block 17 and second drilling angle steel 18; both sides of the test pile 6 are vertically engraved with grooves with a cross-section of 5 mm × 5 mm, and a self-compensating fiber grating strain sensor string 13 with a dense upper structure and a sparse lower structure is embedded Installed in the groove of the test pile 1 and sealed with structural glue, the self-compensating fiber grating strain sensor string 13 is electrically connected with the fiber grating sensor demodulator 15; the engineering pile 1 provides the reaction force for the test pile 6, and the selected bearing capacity is greater than or equal to the test The adjacent pile of pile 6; the engineering pile 1 is connected with the jack 3 through the steel plate cushion block 2, and the number of the steel plate cushion block 2 is determined according to the distance between the test pile 6 and the engineering pile 1, so as to ensure that the engineering pile 1 can fully provide force; under the jack 3, a block 17 is placed, the load sensor 4 is in contact with the pressure end of the jack 3, and is used to accurately measure the pressure value applied by the jack 3, and the load sensor 4 is connected with the load sensor display 14; the spherical hinge support One side 5 is in contact with the load sensor 4, and the other side is in contact with the test pile 6 to ensure that the force applied by the jack 3 acts on the test pile 6 evenly; the two sides of the test pile 6 parallel to the horizontal force center are fixed with expansion screws The first bored angle steel 16 is installed, and the test pile 6 is fixedly installed with the second drilled angle steel 18 in the same way as the test pile 6 is parallel to the center of the horizontal force 50cm upwards. The second drilled angle steel 16 and the second drilled The first dial gauge 7 and the second dial gauge 10 are respectively fixedly installed on the hole angle steel 18, and the dials of the first dial gauge 7 and the second dial gauge 10 are all parallel to the ground; the end of the test pile 6 away from the jack 3 The first reference beam 9 is supported at 630 cm away from the test pile, and the first dial indicator 7 is connected with the first magnetic watch base 8 placed on the first reference beam 9; Two reference beams 12, the second reference beam 12 is 10cm apart from the first reference beam 9, and the height of the second reference beam 12 is higher than the first reference beam 9, at the same position as the first reference beam 9 on the second reference beam 12 A second magnetic base 11 connected to the second dial gauge 10 is placed correspondingly.

The engineering pile 1 described in this embodiment includes a prestressed hollow pipe pile, a prestressed hollow square pile and a solid square pile.

In this embodiment, the test process for realizing the horizontal displacement of the prefabricated pile and the stress of the pile body is as follows:

(1) Before pressing the pile, carve 5mm×5mm grooves on both sides of the test pile 6, put the prefabricated self-compensating fiber grating strain sensor string 13 into the two grooves, and seal them with structural glue , after two days of maintenance, the self-compensating fiber grating strain sensor string 13 forms a dense structure at the top and sparse at the bottom;

(2) When the test pile can be used normally, select a suitable engineering pile 1 to provide a reaction force to ensure that its bearing capacity is greater than or equal to the test pile 6;

(3) Between the test pile 6 and the engineering pile 1, the spherical hinge support 5, the load sensor 4, the jack 3, and the steel plate spacer 2 are placed in sequence. The distance between them is determined to ensure that the engineering pile 1 can fully provide the reaction force. A pad 17 is placed under the jack 3 to ensure that the action centroid of the jack 3 coincides with the center of each part of the test device, and the center of each test device component and the embedded self-compensation The fiber grating strain sensor string 13 is vertical;

(4) Use a drilling rig to drill two holes on both sides of the test pile 6 parallel to the center of the horizontal force, and fix the drilled angle steel 16 with expansion screws. In the same way, place 50 cm above the two sides of the first drilled hole angle steel 16. Fix the second drilling angle steel 18;

(5) support the first reference beam 9 at the end of the test pile 6 away from the jack 3 at 630cm from the test pile and place the first magnetic gauge base 8 on the first benchmark beam 9, and fix the first dial gauge 7 on the first drill On the hole angle steel 16, the dial of the first dial indicator 7 is parallel to the ground; the second reference beam 12 is fixed on the side away from the jack 3 on the second reference beam 9, and the distance between the second reference beam 12 and the first reference beam 9 is 10 cm to ensure that the first Two reference beams 12 are higher than the first reference beam 9, put the second magnetic watch base 11 on the second reference beam 12, the second dial indicator 10 is fixed on the second drilling angle steel 18, the second dial indicator 10 dial parallel to the ground;

(6) The self-compensating fiber grating strain sensor string 13 is connected with the fiber grating sensor demodulator 15, and the load sensor 4 is connected with the load sensor display device 14;

(7) After checking that the components of the test device are installed correctly, perform a load test on the test pile 6 according to the corresponding specifications, record the corresponding displacement and stress change values, and complete the test of the horizontal displacement and pile body stress of the prefabricated pile.

Claims (2)

1. a kind of prefabricated pile Horizontal Displacement and pile body stress joint test device are it is characterised in that agent structure includes engineering Stake, steel plate cushion block, jack, load transducer, spherical hinged-support, test pile, the first dial gauge, the first Magnetic gauge stand, first Datum line beam, the second dial gauge, the second Magnetic gauge stand, the second datum line beam, self-compensation fiber grating strain transducer string, load sensing Device display instrument, fiber grating sensor demodulator, the first boring angle steel, cushion block and the second boring angle steel；The both sides of test pile are erected To be carved with cross section be 5mm × 5mm groove, the embedded peace of self-compensation fiber grating strain transducer string of upper tightly lower sparse structure It is contained in the groove of test pile and with structure glue sealing, self-compensation fiber grating strain transducer string and fiber-optic grating sensor solution Adjust instrument electrical connection；Engineering pile is connected with jack by steel plate cushion block, the number of steel plate cushion block according to test pile and engineering pile it Between distance determine, be placed with cushion block under jack, load transducer contacts with the pressure end of jack, for accurately measurement The pressure value that jack applies, load transducer is connected with load transducer display instrument；The side of spherical hinged-support is passed with load Sensor contacts, and opposite side is contacted with test pile, and test pile adopts setscrew solid with the both sides at horizontal force action center parallel Dingan County equipped with the first boring angle steel, test pile with horizontal force action center parallel up at 50cm both sides upright position with identical Mode is installed with the second boring angle steel, and the first boring angle steel and the second boring angle steel are installed with the first percentage respectively Table and the second dial gauge, the dial plate of the first dial gauge and the second dial gauge is all parallel to the ground；Test pile is away from the one of jack At the distance test stake 30cm of end, first Magnetic gauge stand having placement on the first datum line beam, the first dial gauge and the first datum line beam connects Connect；First datum line beam is fixed with the second datum line beam, the second datum line beam and the first datum line beam 10cm apart away from the side of jack, And second benchmark depth of beam be higher than the first datum line beam, corresponding with the first datum line beam same position on the second datum line beam be placed with The second Magnetic gauge stand being connected with the second dial gauge.

2. according to claim 1 prefabricated pile Horizontal Displacement and pile body stress joint test device it is characterised in that institute State engineering pile and include pre stressed empty piped piles, pre-stress hollow square pile and solid square pile.