System and method for monitoring earth pressure and displacement of miniature steel pipe pile body

Patent metadata

Field	Value
Publication number	US-2022145574-A1
Application number	US-202217581912-A
Country	US
Kind code	A1
Filing date	Jan 22, 2022
Priority date	Jul 31, 2019
Publication date	May 12, 2022
Grant date	—

Abstract

A system and method for monitoring an earth pressure and displacement of a miniature steel pipe pile body. Sensor installation holes are drilled at predetermined positions outside the steel pipe pile body and sensor metal protective shell with a thickness slightly lower than that of the XY-TY02A resistance-type miniature earth pressure gauge is welded on the steel pipe pile body. The XY-TY02A resistance-type miniature earth pressure gauges are stuck on the steel pipe pile body. The transmission line of the XY-TY02A resistance-type miniature earth pressure gauges passes through the sensor installation holes and are connected to data acquisition system. The reflective sheet base is welded at the preset position of the miniature steel pipe pile and the reflective sheet is attached to the reflective sheet base to realize displacement monitoring.

First claim

1 . An earth pressure and displacement monitoring system of a miniature steel pipe pile body, comprising
a plurality of resistance-type miniature earth pressure gauges, a plurality of sensor metal protective shells, a resistance test strain gauge, a data storage device, a reflective sheet, a reflective sheet end support plate, and a reflective sheet base rebar end; wherein a plurality of sensor installation holes are arranged on the miniature steel pipe pile body; the resistance-type miniature earth pressure gauge is embedded in the sensor installation hole; the sensor metal protective shell is arranged at a position where the resistance-type miniature earth pressure gauge will be installed, a sensor is connected to the resistance test strain gauge through a transmission line, and the resistance test strain gauge is connected to the data storage device; a top beam is installed on a top of the miniature steel pipe pile body, and waist beams are evenly distributed on an outer surface, of the miniature steel pipe pile body; the reflective sheet base rebar end is vertically welded at a position which is on the top beam and symmetrical to the sensor installation hole; a protruding end of the reflective sheet base rebar end is provided with the reflective sheet end support plate, and the reflective sheet is installed on, the reflective sheet end support plate.

2 . The earth pressure and displacement monitoring system of claim 1 , wherein vertical symmetry axes of the plurality of sensor installation holes are aligned along a vertical direction of the miniature steel pipe pile body, and a centroid of a cross section of each sensor installation hole coincides with a centroid of a load-hearing membrane side of a corresponding resistance-type miniature earth pressure gauge.

3 . The earth pressure and displacement monitoring system of claim 1 , wherein the plurality of sensor metal protective shells are made of seamless steel pipe with a same material but different sizes as the miniature steel pipe pile body.

4 . The earth pressure and displacement monitoring system of claim 1 , wherein the sensor metal protective shells are arranged by welding on positions where the resistance-type miniature earth pressure gauges will be installed on an outer surface of the miniature steel pipe pile body.

5 . The earth pressure and displacement monitoring system of claim 1 , wherein positions where the resistance-type miniature earth pressure gauges will be installed are polished with an electric polisher and an arc part of the miniature steel pipe pile body is leveled.

6 . The earth pressure and displacement monitoring system of claim 1 , wherein the resistance-type miniature earth pressure gauges adopt a bottom line outlet mode, and a bottom side with a line outlet of each resistance-type miniature earth pressure gauge is aligned with a corresponding sensor installation hole and installed in the sensor installation hole, and the resistance-type miniature earth pressure gauges are stuck on the miniature steel pipe pile body.

7 . The earth pressure and displacement monitoring system of claim 1 , wherein a number of the resistance-type miniature earth pressure gauges is determined by a length of the miniature steel pipe pile body and a number of pre-stressed anchor rods.

8 . The earth pressure and displacement monitoring system of claim 1 , wherein the reflective sheet base rebar end protrudes a distance from the top beam and the miniature steel pipe pile body.

9 . An assembly method of the earth pressure and displacement monitoring system of the miniature steel pipe pile body according to claim 1 , comprising:
(1) checking whether the resistance-type miniature earth pressure gauges are able to work normally; (2) determining positions and size of the sensor installation holes on an outer wall of the miniature steel pipe pile body according to the position where the miniature earth pressure gauge will be installed; and forming the sensor installation holes on the miniature steel pipe pile body; wherein the centroid of the cross section of each sensor installation hole coincides with the centroid of the load-bearing membrane side of corresponding resistance-type miniature earth pressure gauge; after the miniature steel pipe pile body is cooled, polishing the position where the resistance-type miniature earth pressure gauge will be installed on the outer wall of the miniature steel pipe pile, and leveling the arc part of the miniature steel pipe pile body; (3) welding the sensor metal protective shell at the position where the resistance-type miniature earth pressure gauge will be installed on the outer wall of the miniature steel pipe pile body; wherein the sensor metal protective shell is slightly lower than the resistance-type miniature earth pressure gauge in a length direction of the sensor metal protective shell; (4) passing the transmission line of each resistance-type miniature earth pressure gauge from the sensor installation hole into inside of the miniature steel pipe pile body; inserting the resistance-type miniature earth pressure gauge into the sensor metal protective shell and sticking the resistance-type miniature earth pressure gauge on the miniature steel pipe pile body; wherein the load-bearing membrane side of the resistance-type miniature earth pressure gauge faces an earth body; connecting the resistance-type miniature earth pressure gauges to the resistance test strain gauge and the data storage device after the resistance-type miniature earth pressure gauges being firmly stuck; checking a survival rate of the resistance-type miniature earth pressure gauges to make it not lower than a set value; and replacing damaged resistance-type miniature earth pressure gauge with undamaged ones.

10 . A method for monitoring the earth pressure and displacement of the miniature steel pipe pile body by using the earth pressure and displacement monitoring system of the miniature steel pipe pile body according to claim 1 , comprising:
(1) determining a construction spot of a miniature steel pipe pile in a construction site, and drilling a pile hole by using a down-the-hole drilling technology; wherein a diameter of the pile hole is slightly larger than a diameter of the miniature steel pipe pile; twitching up and down a drill stem to facilitate clearing the pile hole; placing the miniature steel pipe pile provided with the resistance-type miniature earth pressure gauges in the drilled pile hole and delivering to a design elevation of the miniature steel pipe pile; (2) inserting a grouting pipe into a bottom of the miniature steel pipe pile, and injecting a mixed cement slurry into the miniature steel pipe pile through a grouting machine; wherein a process that the grouting pipe is inserted first and then the mixed cement slurry is injected is adopted; grouting holes are arranged on the miniature steel pipe piles in a vertical direction; during grouting process, a grouting pressure is ensured to reach a set value at all times; after grouting, the grouting pipe is not immediately pulled out; pulling out the grouting pipe to complete the grouting when the mixed cement slurry flows out of the miniature steel pipe pile again; (3) forming a hole at a top position of the top beam; inserting the reflective sheet base rebar end into the top beam; filling a gap between the reflective sheet base rebar end and the top beam with cement slurry, and fixing the reflective sheet base rebar end and the top beam with expansion bolts; and sticking the reflective sheet on the reflective sheet end support plate after a strength of the filled cement slurry meets design requirements; aiming, by an external total station, at a crosshair of the reflective sheet t

Assignees

• Univ Qingdao Technology
• Qingdao Green Tech Geotechnical Engineering Co Ltd
• Univ Chongqing

Inventors

• Wang Yonghong
• Yang Shujuan
• Zhang Wengang
• Wu Jiangbin
• Huang Jian
• Zhang Qianqing
• Zhang Qijun
• Su Lei
• Yuan Bingxiang
• Cui Jifei
• Fang Xiang
• Zhang Chuantong
• Shao Guodong
• Li Zhaolong
• Cui Lin

Classifications

• E02D1/00

  Investigation of foundation soil in situ (investigation involving boring or specially adapted to earth drilling E21B25/00, E21B49/00; investigating or analysing materials by determining their chemical or physical properties, in general G01N, e.g. sampling G01N1/00) · CPC title

• E02D5/30

  made of concrete or reinforced concrete or made of steel and concrete {(E02D5/50 takes precedence; assembled from segments E02D5/523; prestressed concrete E02D5/58)} · CPC title

• E02D33/00 Primary

  Testing foundations or foundation structures (testing methods and apparatus, see the relevant subclasses of class G01; testing structures or apparatus as regards function, in general, G01M; testing or determining chemical or physical properties, in general G01N) · CPC title

• E02D2250/003

  Injection of material · CPC title

• E02D2300/0029

  Steel; Iron · CPC title