CN206521775U - A kind of pile foundation bearer properties model test apparatus pushed under action of static load - Google Patents

Abstract

The utility model relates to a load-bearing characteristic model test device of a pile foundation under the action of a down-pressing static load, which comprises a model box, a pile model, a vertical down-pressing loading system and a measuring device. The model box is a ribbed steel box with an upper opening; the pile foundation model is connected with the loading lever assembly and set in the model box; the vertical downward pressure loading system is composed of the loading lever assembly, vertical guide rails and weights; the measurement The device includes a total of four dial gauges for measuring the vertical settlement of the pile top. The test device has a wide range of applications, is easy to load, and the model pile is stable under load. It can accurately measure the vertical displacement of the pile top of the pile foundation model, and can conveniently and effectively carry out the model test of the bearing characteristics of the pile foundation under the action of static load. Research.

Description

A model test device for bearing characteristics of pile foundation under static load

technical field

The utility model relates to a pile foundation model test device, in particular to a pile foundation bearing characteristic model test device under the action of down-pressing static load.

Background technique

Compared with conventional bored piles, the pile foundation has the advantages of higher bearing capacity, small construction site, fast construction speed, strong adaptability to soil layers, and flexible layout. It has been widely used in engineering fields such as flood control dam reinforcement and building reinforcement.

For the research on the compressive bearing characteristics of pile foundations, there are mainly field tests and indoor model tests. Although the field test can better reflect the actual situation of the project, it cannot be widely used due to the limitations of limited site space, tight construction schedule, difficulty in embedding instruments and equipment, and high cost. The indoor model test can carry out targeted and repeatable research on the main aspects of the main problems of the project to make up for the shortcomings of the field test, thus becoming one of the effective methods to study and guide the design and solve practical engineering problems. In view of the above reasons, it is particularly important to conduct indoor model tests.

The key technology of the indoor model test of pile compressive bearing characteristics is how to load the model pile simply, quickly and effectively. In the traditional pile foundation model test device, the vertical downward pressure load is usually applied through heap load or jack and reaction beam. , the oil pressure of the jack is unstable, and the load cannot be maintained for a long time. The measuring range is too large for the load of the pile foundation model test, and it cannot be loaded accurately. Moreover, there is no measuring device for the vertical displacement of the pile top, so that the test results cannot accurately reflect The actual situation. Therefore, it is an important task to design a model test device that is easy to manufacture, easy to load, stable under load, and can effectively and accurately measure the vertical displacement of the pile top with the change of the vertical downward load to obtain the compressive bearing characteristics of the pile. Very rewarding work.

Utility model content

In order to solve the technical defects existing in the current pile foundation model test device, the utility model provides a pile foundation bearing characteristic model test device under the action of down-pressing static load with wide application range, simple and convenient loading method and high accuracy.

The technical scheme adopted by the utility model is: a model test device for bearing characteristics of pile foundations under the action of down-pressing static load, which consists of a model box, a pile foundation model, a vertical down-pressing loading system and a measuring device;

In order to facilitate the observation of the test state and ensure the strength of the model box, the model box is a ribbed steel box with an opening at the top, with channel steel reinforcing hoops on the outside, and a pile foundation model inside. The model box is made of ribbed steel plate, two upper and lower layers of channel steel reinforcing hoops are arranged outside the model box, one channel steel reinforcing hoop is arranged horizontally at the upper opening of the model box, and two channel steel reinforcing hoops are arranged longitudinally in parallel.

The composition of described vertical downward pressure loading system comprises loading lever assembly, vertical guide rail and weight; Pile foundation model is connected with loading lever assembly, and is arranged in the model box; Described loading lever assembly comprises loading lever, loading rod, The fixed hinge support, steel wire and weight plate, in order to maintain the stability of the vertical downward loading direction, and at the same time make the whole set of downward loading system detachable, the top of the loading rod and the loading lever are connected by bolt hinge connection, loading One end of the fulcrum of the lever is connected to the fixed hinge support through a bolt hinged connection. The fixed hinge support is fixedly welded to the channel steel reinforcing hoop on the upper layer outside the model box. The other end of the loading lever is provided with a reserved hole. One end of the steel wire Pass through the reserved hole of the loading lever and connect with the loading lever, the other end of the steel wire is connected with the weight plate, and the steel wire keeps the vertical direction; the weight is applied on the weight plate; the pile foundation model is connected with the bottom of the loading bar terminal connection;

The measuring device includes a dial gauge and a dial gauge support for measuring the vertical settlement of the pile top.

A vertical guide rail is vertically provided in the middle of the channel steel reinforcing hoop arranged horizontally in the model box, and the loading rod passes through the inside of the vertical guide rail and can move up and down in the vertical direction along the vertical guide rail.

The top of the pile foundation model is provided with a pile head protection ring and a backing plate successively, the material of the pile head protection ring is rubber, and the backing plate is a square plank; the pile head protection ring is used to protect the pile head of the pile foundation model, as a pile foundation model The bearing point of the downward pressure load, the backing plate is used to adjust the contact between the pile foundation model and the loading bar.

The measuring device is provided with four dial gauges, and all of them are symmetrically fixed on the four corners of the square backing plate along the vertical stress direction of the pile foundation model. The gauges are respectively provided with dial indicator brackets correspondingly, and the dial gauge brackets are respectively located on two channel steel reinforcing hoops arranged longitudinally and parallelly in the model box.

The backing plate is arranged under the loading bar and the loading bar is fixed on the backing plate by bolts.

The loading lever is H-shaped steel, which has high rigidity and is not easily deformed, so that loading can be carried out more effectively and the accuracy of the test can be improved.

The dial gauge is a digital display electronic dial gauge with high precision, intuitive reading and memory function, so that the pile top displacement can be accurately and effectively measured.

The weights can apply different downloads to the model piles through different combinations, and the controllable range is wide, especially when the required download is small, it can be loaded more accurately and effectively, so that the model piles Stable loading and convenient loading.

Compared with the prior art, the utility model has the following advantages:

1. The pile foundation model test device of the present utility model has a wide application range, simple manufacture, simple and convenient loading, high accuracy, and the model pile is stable under load. It breaks through the traditional test device and can only use the jack and the reaction beam to realize the vertical Limitations of downward pressure loading;

2. The utility model uses the principle of leverage to flexibly adjust the positions of the power point and the main force point, thereby greatly reducing the difficulty of the test;

3. The utility model can save loading force by changing the force arm;

4. The loading method of the utility model is greatly simplified, and the purpose of applying different loads can be achieved only by placing different weights on the weight plate outside the model box, and the controllable range is wide, especially when the required pressing load is required. When it is small, it can be loaded more accurately and effectively, so that the model pile can be loaded stably and loaded conveniently;

5. The utility model can effectively measure the change of the vertical displacement of the pile top with the vertical downward pressure load, and the reading is accurate and intuitive, so as to obtain the compressive bearing characteristics of the pile.

Description of drawings

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

Fig. 1 is the front view of the utility model;

Fig. 2 is the top view of the utility model;

Fig. 3 is a partial side view of the vertical guide rail of the present utility model;

In the figure: 1. Model box; 2. Model soil; 3. Channel steel reinforcing hoop; 4. Loading lever; 5. Bolt; 6. Pile foundation model; 7. Dial indicator; 8. Loading rod; 9. Vertical Guide rail; 10. Reserved hole; 11. Steel wire; 12. Weight plate; 13. Fixed hinge support; 14. Pile head protection ring; 15. Backing plate; 16. Dial indicator support.

detailed description

As shown in Figures 1 to 3, a model test device for the bearing characteristics of a pile foundation under the action of a downward static load includes a model box 1, a pile foundation model 6, a vertical downward pressure loading system and a measuring device;

In order to facilitate the observation of the test state and ensure the strength of the model box 1, the model box 1 is a ribbed steel box with an upper opening, and a channel steel reinforcing hoop 3 is arranged outside it, and a pile foundation model 6 is placed inside.

The model box 1 is made of ribbed steel plates. There are upper and lower layers of channel steel reinforcement hoops 3 outside the model box 1. A channel steel reinforcement hoop 3 is arranged horizontally at the upper opening of the model box 1, and two parallel channel steel hoops are arranged longitudinally. Channel steel reinforcement hoop 3.

The composition of the vertical downward pressure loading system includes a loading lever assembly, a vertical guide rail 9 and weights; The loading lever assembly includes a loading lever 4, a loading rod 8, a fixed hinge support 13, a steel wire 11 and a weight plate 12, in order to maintain the stability of the vertical downward loading direction, and at the same time make the whole set of downward loading system detachable , the top of the loading rod 8 is connected with the loading lever 4 through the hinged connection mode of the bolt 5, and one end of the fulcrum of the loading lever 4 is connected with the fixed hinge support 13 through the hinged connection mode of the bolt 5, and the fixed hinge support 13 is fixedly welded on the model On the channel steel reinforcing hoop 3 on the outer upper layer of the box 1, the other end of the loading lever 4 is provided with a reserved hole 10, and one end of the steel wire 11 passes through the reserved hole 10 of the loading lever 4 to be connected with the loading lever 4, and the other end of the steel wire 11 is connected to the loading lever 4. One end is connected with the weight plate 12, and the steel wire 11 maintains a vertical direction; the weight is applied on the weight plate 12; the pile foundation model 6 is connected with the bottom end of the loading rod 8;

The measuring device includes a dial indicator 7 and a dial indicator support 16 for measuring the vertical settlement of the pile top.

The channel steel reinforcing hoop 3 middle part that is arranged horizontally in the opening of the model box 1 is vertically provided with a vertical guide rail 9, and the loading rod 8 passes through the inside of the vertical guide rail 9, and the loading rod 8 is horizontally moved by the vertical guide rail 9. Constrained, and can move up and down in the vertical direction along the vertical guide rail 9.

The top of the pile foundation model 6 is successively provided with a pile head protection ring 14 and a backing plate 15, the material of the pile head protection ring 14 is rubber, and the backing plate 15 is a square plank; the pile head protection ring 14 is used to protect the pile foundation model 6. The pile head is used as the point where the pile foundation model 6 is subjected to the downward pressure load, and the backing plate 15 is used to adjust the contact between the pile foundation model 6 and the loading rod 8 .

The measuring device is provided with four dial gauges 7, and the dial gauges 7 are symmetrically fixed to the four corners of the square backing plate 15 along the vertical stress direction of the pile foundation model 6, and the dial gauges 7 are maintained vertically. Straight, the measuring head contacts the backing plate 15, and each dial indicator 7 is respectively provided with a dial indicator support 16 correspondingly, and the dial indicator support 16 is respectively located on two channel steel reinforcing hoops 3 arranged longitudinally parallel to the opening in the model box 1.

The backing plate 15 is arranged under the loading bar 8 and the loading bar 8 is fixed on the backing plate 15 by bolts.

The loading lever 4 is H-shaped steel, which has high rigidity and is not easily deformed, so that loading can be carried out more effectively and the accuracy of the test can be improved.

The dial gauge 7 is a digital display electronic dial gauge with high precision, intuitive reading and memory function, so that the pile top displacement can be accurately and effectively measured.

The weights can apply different downloads to the model piles through different combinations, and the controllable range is wide, especially when the required download is small, it can be loaded more accurately and effectively, so that the model piles Stable loading and convenient loading.

The working process of this device: the model soil 2 used for the test is filled in the model box 1, the pile foundation model 6 is embedded in the model soil 2, and the half-mode or full-mode test of the pressure bearing characteristics of the single pile and pile group foundation can be carried out, and the adjustment The position of the loading lever 4 makes the loading lever 8 and the pile foundation model 6 in the same plane; adjust the position of the loading lever 8 on the loading lever 4 so that the bottom of the loading lever 8 is aligned with the upper center of the pile foundation model 6 and fixed; Pile head protection ring 14 and backing plate 15 are arranged successively at the pile top of pile foundation model 6; There are four submeters 7, which are installed on the dial gauge support 16. The dial gauges 7 are all symmetrically fixed on the four corners of the square backing plate 15 along the vertical stress direction of the pile foundation model 6. The body of the dial gauge 7 Keep it vertical, and the measuring head touches the backing plate; select the loading scheme and termination loading standard according to the "Technical Specifications for Testing of Building Pile Foundations" (JGJ 106-2014), and estimate the ultimate compressive bearing capacity of the pile foundation model 6. By adding weight control on the code disc 12, the vertical downward pressure load can be applied to the pile foundation model 6, and the loading situation (load size) can be recorded in time; data can be collected through the measuring device, and the pile top of the pile foundation model 6 can be recorded The vertical displacement is measured and the average value of the four data is taken to analyze the compressive bearing characteristics of the pile foundation model 6.

Claims (7)

1. a kind of pile foundation bearer properties model test apparatus pushed under action of static load, it is characterised in that its composition includes mould Molding box, pile foundation model, vertically push loading system and measurement apparatus；

The model casing is to lay pile foundation model in the ribbing steel casing of upper opening, model casing；Set outside model casing A channel-section steel Reinforced Hoop, parallel longitudinal setting are horizontally arranged with two layers of channel-section steel Reinforced Hoop above and below having, model casing internal upper part opening There are two channel-section steel Reinforced Hoops；

The vertical composition for pushing loading system includes loading lever assembly, vertical guide and counterweight；

The loading lever assembly includes loading lever, load bar, fixed-hinged support, wire and scale pan, load bar top It is connected with loading lever by the connected mode of bolted splice, loads the connection side that fulcrum one end of lever passes through bolted splice Formula is connected with fixed-hinged support, and fixed-hinged support is fixedly welded on the channel-section steel Reinforced Hoop on the outer upper strata of model casing, loads lever The other end be provided with preformed hole, wire one end is connected through the preformed hole of loading lever with loading lever, and wire is another One end is connected with scale pan, and wire keeps vertical direction；Counterweight is put on scale pan；The pile foundation model and loading Bar bottom is connected;

The measurement apparatus includes the amesdial and dial indicators rack of measurement stake top Vertical Settlement amount.

2. a kind of pile foundation bearer properties model test apparatus pushed under action of static load according to claim 1, it is special Levy and be, vertical guide, the loading are offered vertically in the middle part of the channel-section steel Reinforced Hoop laterally set at the model casing inner opening Bar can be moved vertically under guide rail in the vertical direction through inside vertical guide.

3. a kind of pile foundation bearer properties model test apparatus pushed under action of static load according to claim 1, it is special Levy and be, pile crown guard circle and backing plate are disposed with the top of the pile foundation model, backing plate is square plank, pile crown protection Loop material matter is rubber.

4. a kind of pile foundation bearer properties model test apparatus pushed under action of static load according to claim 3, it is special Levy and be, the measurement apparatus is provided with four amesdials, and amesdial is symmetrical along the vertical applied force direction of pile foundation model Four angles of square backing plate are fixed on, amesdial table body keeps vertical, and each amesdial is correspondingly arranged on dial indicators rack, thousand respectively It is divided to table support to be located at respectively at model casing inner opening on two channel-section steel Reinforced Hoops of parallel longitudinal setting.

5. a kind of pile foundation bearer properties model test apparatus pushed under action of static load according to claim 3, it is special Levy and be, the backing plate is arranged on below load bar and load bar is fixed on backing plate by bolt.

6. a kind of pile foundation bearer properties model test apparatus pushed under action of static load according to claim 1, it is special Levy and be, the loading lever is H profile steel.

7. a kind of pile foundation bearer properties model test apparatus pushed under action of static load according to claim 1 or 4, its It is characterised by, the amesdial selects digital display electronic formula amesdial.