CN113529825B - Method for evaluating instability damage of pile hole wall under vibration load - Google Patents

Method for evaluating instability damage of pile hole wall under vibration load Download PDF

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CN113529825B
CN113529825B CN202110892774.XA CN202110892774A CN113529825B CN 113529825 B CN113529825 B CN 113529825B CN 202110892774 A CN202110892774 A CN 202110892774A CN 113529825 B CN113529825 B CN 113529825B
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soil layer
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杨秋伟
孙洋
吴关良
朋茜
徐敬淼
赵�卓
王睢
马永政
巴智坤
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Ningbo University of Technology
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Abstract

The invention discloses an assessment method for instability damage of a pile hole wall under a vibration load, and relates to the field of pile foundation engineering. The method comprises the following steps: calculating a hole collapse control function of the depth below the horizontal ground according to a soil geological exploration report of a construction site and construction equipment parameters; digging a vertical speed measuring hole 1m near the position of a pile hole to be drilled for testing and obtaining the vibration speed of the nearby vibration load on the soil body; solving a collapse function caused by vibration; and finally, comparing the size between the hole collapse control function and the collapse causing function, and solving a hole wall stability safety factor and a vibration speed safety threshold, wherein the safety factor is larger than 1, which indicates that the hole wall is safe, and the larger the numerical value of the safety factor is, the higher the hole wall stability safety degree is. The method can evaluate the stability and safety degree of the wall of the pile hole, obtain the stability safety factor and the vibration safety speed threshold of the wall of the pile hole, avoid hole collapse damage and guarantee construction safety.

Description

Method for evaluating instability damage of pile hole wall under vibration load
Technical Field
The invention relates to the field of pile foundation engineering of civil engineering discipline, in particular to a method for evaluating instability damage of a pile hole wall under a vibration load.
Background
The cast-in-situ bored pile is widely applied to house construction, bridges and port engineering, and is made into a pile foundation by forming a pile hole in foundation soil through means of mechanical drilling, steel pipe soil extrusion or manual excavation and the like, and then placing a reinforcement cage in the pile hole and pouring concrete. In the construction process of the bored pile, vibration impact loads (such as vibration impact effect caused by piling, blasting and the like in an adjacent field) often exist in the adjacent area, and the vibration loads may damage the stability of the wall of the pile hole, so that hole collapse damage occurs, subsequent cast concrete cannot be performed, and the construction safety, the construction quality and the construction progress are seriously affected. Therefore, before the construction of the cast-in-situ bored pile, whether the wall of the pile hole is subjected to instability damage under the action of vibration load is evaluated, a vibration safety speed allowable value is given, the construction process is guided accordingly, the hole collapse damage is avoided, and the construction safety is guaranteed. However, in the existing analysis method about the instability damage of the pile hole wall, the effect of the vibration load is rarely involved, and an evaluation method for the instability damage of the pile hole wall under the vibration load is urgently needed.
Disclosure of Invention
In view of the above, the invention provides an evaluation method for destabilization damage of a pile hole wall under a vibration load, which can evaluate the stability and safety degree of the pile hole wall, obtain a hole wall stability safety factor and a vibration safety speed threshold, guide the construction process according to the safety factor, avoid the occurrence of hole collapse damage and guarantee the construction safety.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for evaluating instability damage of a pile hole wall under a vibration load comprises the following steps:
obtaining construction site parameters, and calculating a hole collapse control function t(h)；
Obtaining a vertical speed measuring hole and the vibration speed of the vibration load on the soil body
Figure BDA0003196611790000021
Using speed of vibration
Figure BDA0003196611790000022
Solving collapse function kappa of ith soil layeri；
According to the hole collapse control function t(h)With said collapsing function kiAnd judging whether the hole wall is safe or not.
Preferably, the hole collapse control function t(h)The calculation formula is as follows:
Figure BDA0003196611790000023
Figure BDA0003196611790000024
wherein, subscript "i" represents the soil layer number corresponding to the depth h; deltaiRepresenting a direction conversion coefficient of an ith soil layer; oiRepresenting Poisson's ratio, theta, of the i-th soil layeriRepresenting the friction angle of the ith soil layer; tau isiRepresents the cohesive force upsilon of the ith soil layerjRepresenting the natural gravity of the jth soil layer; ljRepresenting the thickness of the jth soil layer; mu denotes the weight of the retaining wall slurry used in the drilling, y0Indicating the height of the slurry level above the horizontal ground, y1The height of the mud liquid level drop when the drilling machine lifts the drill is shown; η represents a suction stress caused by the drilling machine, and ζ represents a vertical stress generated by a construction load gravity on the ground when drilling is performed.
Preferably, the vibration speed is obtained as follows:
arranging three speed sensors from top to bottom in the vertical speed measuring hole, connecting the three speed sensors with a data acquisition instrument to obtain three speed values, calculating an average value to obtain the vibration speed
Figure BDA0003196611790000025
Preferably, the collapse function κiThe calculation formula is as follows:
Figure BDA0003196611790000026
wherein, thetaiRepresenting the friction angle, p, of the i-th soil layeriRepresenting the density of the ith soil layer;
Figure BDA0003196611790000027
and expressing the longitudinal wave propagation coefficient of the ith soil layer.
Preferably, said safety threshold value v for the vibration speedsecThe calculation formula of (2) is as follows:
Figure BDA0003196611790000031
judging whether the vibration speed is less than a safety threshold value vsecAnd if not, reducing the vibration load intensity.
Preferably, the specific method for judging whether the hole wall is safe is as follows:
comparing hole collapse control functions t(h)And collapse function κiIf t is(h)≥κiThe safety factor chi of the stability of the hole wall and the safety factor of the hole wall are shown(h)Calculated by the following formula:
Figure BDA0003196611790000032
safety factor chi(h)If the value is more than 1, the safety factor chi indicates that the hole wall is safe(h)The larger the numerical value of (A) is, the higher the stability and safety degree of the hole wall is; if t is(h)＜κiThe hole wall is unsafe.
According to the technical scheme, compared with the prior art, the invention discloses the method for evaluating the instability damage of the wall of the pile hole under the vibration load, which can evaluate the stability safety degree of the wall of the pile hole, obtain the safety factor of the wall stability and the vibration safety speed threshold value, guide the construction process according to the safety factor, avoid the collapse damage and guarantee the construction safety.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic diagram of a basic engineering project of the present invention;
FIG. 2 is a schematic diagram of an evaluation process according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention discloses a method for evaluating instability and damage of a pile hole wall under a vibration load, which comprises the following steps:
a pile foundation engineering project, as shown in fig. 1, is divided into seven soil layers from top to bottom, and a bored pile is adopted, so that a blasting engineering project is developed in the adjacent area while the pile foundation is constructed, and the stability of the wall of the pile hole in the construction process is evaluated, wherein the process of evaluating the stability of the wall of the pile hole by using the method of the invention is as follows:
(1) according to the geological exploration report of the soil body of the construction site and the parameters of the construction equipment, the physical parameters of all the soil layers are listed in a table 1, and the parameters of the drilling machine equipment are listed in a table 2.
TABLE 1 soil layer physical parameter table
Figure BDA0003196611790000041
TABLE 2 rig equipment parameters
Serial number Parameter(s) Value of
1 Weight mu of wall mud used in drilling 12kN/m3
2 Height y of mud level above horizontal ground0 2m
3 Height y of mud liquid level drop when drill rig lifts 1 1m
4 Rig induced suction stress eta 35kPa
5 Vertical stress zeta generated by construction load gravity on ground during drilling construction 25kPa
Calculating a hole collapse control function t at the depth h below the horizontal ground(h)The calculation formula is as follows:
Figure BDA0003196611790000051
Figure BDA0003196611790000052
in this embodiment, a part of the depth position is selected, and the hole collapse control function t is calculated(h)Are listed in table 3.
(2) As shown in the attached drawing, a vertical speed measuring hole is manually dug at a position 1m close to a pile hole to be drilled for testing and obtaining the vibration speed of the nearby vibration load on the soil body. The size of the speed measuring hole is as follows: diameter 0.1m, vertical depth 2 m. For the speed measuring hole, three speed sensors are arranged from top to bottom, the first speed sensor is arranged on the ground, the second speed sensor is arranged at the position with the depth of 1m, and the third speed sensor is arranged at the bottom of the speed measuring hole. The three speed sensors are connected with a data acquisition instrument, and the sensors and the data acquisition instrument can be purchased from the market, so that three speed values can be obtained and are marked as v from top to bottom(1)、v(2)And v(3)And calculates the average of these three speeds:
Figure BDA0003196611790000053
the speed values obtained by the test of this embodiment are respectively: v. of(1)＝1.05cm/s、v(2)1.02cm/s and v(3)1.1cm/s, average speed
Figure BDA0003196611790000054
(3) Solving collapse function kappa of ith soil layer caused by vibrationiThe calculation formula is as follows:
Figure BDA0003196611790000061
wherein, thetaiRepresenting the ith soil layerAngle of friction (unit: degree), piRepresenting the density of the ith soil layer;
Figure BDA0003196611790000062
and the longitudinal wave propagation coefficient of the ith soil layer is represented, and the values of the parameters can be obtained according to a soil geological exploration report of a construction site. The collapse function κ calculated by the present embodimentiAre listed in table 3.
(4) Finally, the hole collapse control functions t are compared(h)And collapse function κiIf t is(h)≥κiThe safety factor chi of the stability of the hole wall and the safety factor chi of the hole wall are shown(h)Can be calculated by the following formula:
Figure BDA0003196611790000063
safety factor chi(h)If the value is more than 1, the safety factor chi indicates that the hole wall is safe(h)The larger the value of (A) is, the higher the degree of stability and safety of the hole wall is. The safety factor χ calculated in the embodiment(h)Are listed in table 3. If t(h)＜κiIf the hole wall is unsafe, hole collapse damage can occur, and at this time, in order to guarantee construction safety, the vibration load strength needs to be reduced, so that the vibration speed is smaller than a safety threshold, and a vibration speed safety threshold v is adoptedsecThe calculation formula of (2) is as follows:
Figure BDA0003196611790000064
the embodiment calculates the obtained vibration speed safety threshold vsecAre listed in table 3. During actual construction, whether the measured vibration speed is smaller than the vibration speed safety threshold v or not can be observed at any timesecAnd for the unqualified products, the vibration load strength needs to be reduced, so that the hole collapse damage can be avoided.
TABLE 3 calculation results based on the method of the invention
Figure BDA0003196611790000065
Figure BDA0003196611790000071
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (3)

1. A method for evaluating instability damage of a pile hole wall under a vibration load is characterized by comprising the following steps:
obtaining construction site parameters, and calculating a hole collapse control function t(h)Said hole collapse control function t(h)The calculation formula is as follows:
Figure FDA0003625588750000011
Figure FDA0003625588750000012
wherein, subscript "i" represents the soil layer number corresponding to the depth h; deltaiRepresenting a direction conversion coefficient of an ith soil layer; o ° oiRepresenting Poisson's ratio, theta, of the i-th soil layeriRepresenting the friction angle of the ith soil layer; tau isiDenotes the cohesive force of the i-th soil layer, upsilonjRepresenting the natural gravity of the jth soil layer; ljRepresenting the thickness of the jth soil layer; mu denotes the weight of the retaining wall slurry used in the drilling, y0Indicating the level of the slurryHeight above horizontal ground, y1The height of the mud liquid level drop when the drilling machine lifts the drill is shown; η represents a suction stress caused by the drilling machine, and ζ represents a vertical stress generated by a construction load gravity on the ground when drilling construction;
obtaining a vertical speed measuring hole and the vibration speed of the vibration load on the soil body
Figure FDA0003625588750000013
Using speed of vibration
Figure FDA0003625588750000014
Solving collapse function kappa of ith soil layeriThe collapse function κiThe calculation formula is as follows:
Figure FDA0003625588750000015
wherein, thetaiRepresenting the friction angle, p, of the i-th soil layeriRepresenting the density of the ith soil layer;
Figure FDA0003625588750000016
representing the longitudinal wave propagation coefficient of the ith soil layer;
comparing hole collapse control functions t(h)And collapse function κiIf t is(h)≥κiThe safety factor chi of the stability of the hole wall and the safety factor of the hole wall are shown(h)Calculated by the following formula:
Figure FDA0003625588750000017
safety factor x(h)If the value is more than 1, the safety factor chi indicates that the hole wall is safe(h)The larger the numerical value of (A) is, the higher the stability and safety degree of the hole wall is; if t(h)＜κiThe hole wall is unsafe.
2. The method for evaluating the instability damage of the pile hole wall under the vibration load according to claim 1, wherein the vibration speed is obtained as follows:
arranging three speed sensors from top to bottom in the vertical speed measuring hole, connecting the three speed sensors with a data acquisition instrument to obtain three speed values, calculating an average value to obtain the vibration speed
Figure FDA0003625588750000022
3. The method for evaluating the instability damage of the wall of the pile hole under the vibration load according to claim 1, wherein the safety threshold v of the vibration speed issecThe calculation formula of (2) is as follows:
Figure FDA0003625588750000021
judging whether the vibration speed is less than a safety threshold value vsecAnd if not, reducing the vibration load strength.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080093692A (en) * 2007-04-18 2008-10-22 주식회사 대우엔지니어링 Behavior analyzing method of pile-bent structure
CN105484300A (en) * 2016-01-15 2016-04-13 青岛理工大学 Determination method of large-aperture drilling dado reinforcing mud critical proportion
CN106326552A (en) * 2016-08-24 2017-01-11 青岛理工大学 Dynamic compaction reinforcing method for improving stability of cast-in-place pile collapse hole
CN109056847A (en) * 2018-05-30 2018-12-21 北京工业大学 A kind of Vertical Vibration method of large diameter friction piles in overlaying bedrock ground
CN111382517A (en) * 2020-03-16 2020-07-07 上海大学 Pile foundation buckling critical load analytical solution analysis method based on double-parameter foundation model

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080093692A (en) * 2007-04-18 2008-10-22 주식회사 대우엔지니어링 Behavior analyzing method of pile-bent structure
CN105484300A (en) * 2016-01-15 2016-04-13 青岛理工大学 Determination method of large-aperture drilling dado reinforcing mud critical proportion
CN106326552A (en) * 2016-08-24 2017-01-11 青岛理工大学 Dynamic compaction reinforcing method for improving stability of cast-in-place pile collapse hole
CN109056847A (en) * 2018-05-30 2018-12-21 北京工业大学 A kind of Vertical Vibration method of large diameter friction piles in overlaying bedrock ground
CN111382517A (en) * 2020-03-16 2020-07-07 上海大学 Pile foundation buckling critical load analytical solution analysis method based on double-parameter foundation model

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
沿海地区大孔径钻孔灌注桩施工孔壁稳定性数值模拟研究;张嘉鑫等;《工程建设》;20161015(第05期);第1-9页 *
饱和黏土中钻孔灌注桩孔壁稳定性力学机制研究;李林等;《岩土力学》;20160910(第09期);第2496-2504页 *

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