A construction method for an intelligent in-pipe under-reamed pile and an intelligent rammer device

Abstract

The present application relates to a construction method for an intelligent in-pipe under-reamed pile and an intelligent rammer device. The method includes the following steps: S1. Drilling a hole at a set pile position and lowering a retaining wall body to the bearing stratum, or directly pressing the retaining wall body to the bearing stratum to form a pile hole; S2. Filling and ramming the hollow part of the retaining wall body and detecting the lifting force of the rammer; S3. If the lifting force of the rammer is greater than the self-weight of the rammer, it is determined that the rammer is jammed / sucked, and one or a combination of measures such as increasing the filling amount of the next filling material, reducing the lifting height of the rammer, and replacing the filling material with a larger particle size is taken for disposal; S4. Inspecting the compactness of the enlarged head formed by ramming the filling material; S5. Pouring concrete into the hollow part of the retaining wall body to construct the pile body. By monitoring the lifting force of the rammer in real time and comparing the numerical change with the self-weight of the rammer, the present application classifies the sucking / jamming state of the rammer into the pile bottom sucking state and the pipe wall jamming state, and takes targeted pre-disposal measures, which can effectively improve the jamming situation of the rammer.

Description

Technical Field

[0001] The present application relates to the technical field of pile foundation construction, and in particular to a construction method for an intelligent pipe-expanded base pile and an intelligent rammer device. Background Art

[0002] An expanded base pile is a type of pile with a larger-diameter enlarged head connected to the lower part of the pile body. Since the enlarged diameter of the enlarged head can be 1.5 to 4 times larger than the pile body, the single-pile bearing capacity of the expanded base pile can be increased by more than 3 times. Under the same single-pile bearing performance requirements, the pile body length can be reduced by more than 2 times, showing extremely broad development prospects in pile foundation construction.

[0003] Currently, when constructing an expanded base pile, the pile body can be a cast-in-place pile or a precast pipe pile; and the enlarged head can be formed by mechanical methods such as heavy hammer ramming, static pressure, and rotary pressure filling, or can be formed by grouting and curing after rotary excavation of an enlarged base pit at the lower part of the pile body. Among them, the method of ramming the filling material with a heavy hammer to construct the enlarged head is the simplest, and the corresponding construction equipment has a simple structure, comprehensive function integration, more mature technology, and higher intelligence level, which is a commonly used construction method at present.

[0004] However, during the process of ramming the filling material with a heavy hammer, if the water content in the soil layer is relatively high or the groundwater pressure is relatively large, when ramming the filling material with a heavy hammer into such a soil layer, this part of the soil layer will be rammed into a kind of rubbery soil, and in severe cases, it will even cause the hammer to be sucked in; or when ramming the filling material in the pipe, when ramming the filling material with a heavy hammer, part of the filling material will surge downward, and the other part of the filling material will spread to the side and enter the gap between the heavy hammer and the pipe wall. As the ramming operation continues, the filling material in the gap between the heavy hammer and the pipe wall will form a hard cylinder, which will also cause the phenomenon of the hammer being clamped, and in severe cases, it will even cause the pile to burst. Once a serious phenomenon of the heavy hammer being clamped occurs and the heavy hammer cannot be pulled out, a crane needs to be replaced to lift the heavy hammer, which will undoubtedly seriously affect the construction progress; moreover, if an automated pile foundation construction equipment is used for the construction of an expanded base pile, the pile foundation construction equipment cannot judge the situation of the heavy hammer being clamped, and it is very easy to cause serious damage to the pile foundation construction equipment during the process of automatically executing according to the set program. Summary of the Invention

[0005] In order to improve the problem that the phenomenon of the hammer being clamped easily caused during the process of ramming the filling material with a heavy hammer is difficult to solve in time, which causes a great burden on the construction progress and construction cost, the present application provides a construction method for an intelligent pipe-expanded base pile and an intelligent rammer device.

[0006] The following technical solution is adopted for a construction method for an intelligent pipe-expanded base pile provided in the first aspect of the present application:

[0007] A construction method for an intelligent pipe-expanded base pile includes the following steps:

[0008] S1. Form a hole at the set pile position and lower the retaining wall body to the bearing stratum, or directly press the retaining wall body down to the bearing stratum to form a pile hole;

[0009] S2. Put filling materials into the hollow part of the retaining wall body, lift the heavy hammer for ramming, and detect the lifting force of the heavy hammer;

[0010] S3. If the lifting force of the heavy hammer is greater than the self-weight of the heavy hammer after ramming the filling materials, it is determined that the heavy hammer is jammed / absorbed by the pile, and one or a combination of the following methods is adopted for disposal: increasing the filling amount of the next filling material, reducing the lifting height of the heavy hammer, and replacing the filling material with a larger particle size;

[0011] S4. Check whether the compactness of the enlarged head formed by ramming the filling materials meets the construction standards. If the construction is qualified, proceed to the next step; otherwise, continue to put in filling materials and ram them;

[0012] S5. Pour concrete into the hollow part of the retaining wall body to construct the pile body.

[0013] Furthermore, in step S3, if the lifting force first increases slowly and then decreases to the self-weight of the heavy hammer in a short time, it is determined that the heavy hammer is in the state of being absorbed by the pile bottom, and the method of increasing the filling amount of the next filling material and / or reducing the lifting height of the heavy hammer is adopted for disposal;

[0014] If the lifting force rapidly increases to a certain range value and then decreases to the self-weight of the heavy hammer after a certain time, it is determined that the heavy hammer is in the state of being jammed by the pipe wall, and the method of replacing the filling material with a larger particle size and / or reducing the lifting height of the heavy hammer is adopted for disposal.

[0015] Furthermore, in step S3, the bottom elevation of the heavy hammer is also detected. If the bottom elevation of the heavy hammer is lower than the pile bottom elevation before lifting the hammer and the lifting force first increases slowly and then decreases to the self-weight of the heavy hammer in a short time, it is determined that the heavy hammer is in the state of being absorbed by the pile bottom;

[0016] If the bottom elevation of the heavy hammer is not lower than the pile bottom elevation before lifting the hammer and the lifting force rapidly increases to a certain range value and then decreases to the self-weight of the heavy hammer after a certain time, it is determined that the heavy hammer is in the state of being jammed by the pipe wall.

[0017] Furthermore, in step S3, the upward displacement of the heavy hammer from the start of lifting the hammer to the time when the lifting force is just equal to the self-weight of the heavy hammer is detected;

[0018] When it is determined that the heavy hammer is in the state of being absorbed by the pile bottom, if the upward displacement is not greater than the first threshold value, first increase the filling amount of the next filling material and then ram. If the upward displacement of the heavy hammer after continuous ramming for no less than three times does not approach zero after disposal, reduce the lifting height of the heavy hammer;

[0019] If the upward displacement is greater than the first threshold, only take the measure of reducing the lifting height of the rammer or take the measures of reducing the lifting height of the rammer and increasing the filling amount of the next filling material at the same time;

[0020] Until it is determined that the rammer does not suck the hammer, restore the original lifting height of the rammer and the filling amount of the single filling material, and continue to feed and tamp.

[0021] Furthermore, in the step S3, the proportion of coarse aggregate in the replaced large particle size filling material is not less than 50%, and the particle size of the coarse aggregate is greater than the difference between the radius of the rammer and the inner wall of the retaining wall and less than or equal to the difference between the diameter of the rammer and the inner wall of the retaining wall.

[0022] Furthermore, in the step S3, when putting the coarse aggregate, it includes the following steps:

[0023] S31. Lift the rammer until the bottom elevation of the rammer just crosses the pipe wall clamping hammer layer, swing the rammer to one side to form a feeding space between the other opposite side of the rammer and the inner wall of the retaining wall, and then put the coarse aggregate into the feeding space;

[0024] S32. Control the rammer to reciprocate down and up slightly for several times, so that the coarse aggregate scrapes off the pipe wall clamping hammer layer adhered to the inner wall of the retaining wall under the drive of the rammer friction.

[0025] Furthermore, in the step S2, set the zero-point pulling force for lifting the rammer according to the self-weight of the rammer. When the lifting pulling force is greater than or equal to the zero-point pulling force for lifting the rammer and maintains the set time, it is determined that the steel wire rope for lifting the rammer is in a taut state, and then the elevation and displacement of the rammer can be determined according to the walking amount of the steel wire rope.

[0026] Furthermore, in the step S1, if a precast pile is constructed, the retaining wall is a prestressed pipe pile; if a cast-in-situ pile is constructed, the retaining wall is a steel casing;

[0027] When driving the pile, set a bottom seal at the bottom of the retaining wall and press it down to the bearing stratum. After putting the filling material, use the rammer to tamp and break through the bottom seal; or, do not seal the bottom of the retaining wall directly press it down to the bearing stratum, then take soil from the hollow part of the retaining wall to the bearing stratum, and then fill and tamp.

[0028] Furthermore, in the step S4, one of the following methods is used to inspect the enlarged head:

[0029] (1) Lift the rammer with the set lifting height and tamp the filling material. If the sinking amount of the rammer does not increase after continuous N tamping times without filling, the construction of the enlarged head is qualified, where N≥3;

[0030] (2) Measure the three-hit penetration.

[0031] The intelligent rammer equipment provided by the second aspect of the present application adopts the following technical solutions:

[0032] An intelligent rammer equipment, based on the above-mentioned construction method of an intelligent pipe-expanded bottom pile, includes:

[0033] A chassis module for carrying and moving the equipment;

[0034] A support module for supporting and lifting the hanging point of the equipment;

[0035] A ramming module, including a winch, a steel wire rope and a heavy hammer, wherein the steel wire rope is hung on the hanging point of the equipment formed by the support module to lift and lower the heavy hammer;

[0036] A feeding module for conveying filling materials into the pile hole;

[0037] A detection module for detecting the lifting force of the steel wire rope when lifting the heavy hammer, as well as the bottom elevation of the heavy hammer and the upward displacement of the heavy hammer; and

[0038] A control module for controlling the operation of the ramming module and the feeding module according to the detection data of the detection module, and / or for manual control by an operator to control the operation of the ramming module and the feeding module.

[0039] Furthermore, it further includes:

[0040] A data storage module for storing construction data, as well as the detection data and control data of the detection module and the control module;

[0041] A communication module for uploading the data stored in the data storage module to a remote monitoring platform.

[0042] Furthermore, the detection module includes a pressure sensor for detecting the lifting force of the steel wire rope when lifting the heavy hammer and a counter for detecting the running distance of the steel wire rope;

[0043] Set the zero lifting force of the steel wire rope according to the self-weight of the heavy hammer. Only when the detected value of the pressure sensor is greater than or equal to the zero lifting force of the steel wire rope and maintains the set time, after determining that the steel wire rope is in a taut state, the detection data of the counter becomes effective.

[0044] In summary, the beneficial technical effects of the present application are:

[0045] 1. During the heavy hammer ramming process, by monitoring the lifting force of the hammer in real time and comparing the change in its value with the self-weight of the heavy hammer, based on the different characteristics of the change in the lifting force of the heavy hammer in the states of the hammer being sucked at the pile bottom and the hammer being clamped by the pipe wall, the specific distinction and determination of the hammer being sucked / clamped state are determined as the state of the hammer being sucked at the pile bottom and the state of the hammer being clamped by the pipe wall. And for different hammer being sucked / clamped states, by selecting the corresponding single or combined treatment plan from the three treatment plans of increasing the filling material quantity for the next time, reducing the lifting height of the heavy hammer, and replacing the filling material with a larger particle size, the situation of the hammer being clamped during the heavy hammer ramming filling process can be effectively improved;

[0046] 2. By detecting the upward displacement of the heavy hammer from the start of lifting the hammer until the lifting force of the hammer is just equal to the self-weight of the heavy hammer, it can be used to characterize the degree of the heavy hammer being sucked / clamped. The larger the upward displacement, the greater the severity of the heavy hammer being sucked / clamped. And for the state of the hammer being sucked at the pile bottom, a first threshold is set, and the treatment method of increasing the filling material quantity for the next time is preferentially adopted, and then the treatment method of reducing the lifting height of the heavy hammer is adopted as appropriate, so as to ensure that while improving the situation of the heavy hammer being clamped, the impact on the construction efficiency is minimized as much as possible. At the same time, for the state of the hammer being clamped by the pipe wall, the upward displacement can also be used to represent the thickness of the pipe wall clamping layer, and can also be used to determine whether the heavy hammer is sucked / clamped. It can be used as a determination parameter for the state of the heavy hammer being sucked / clamped together with the lifting force, or as a re-inspection parameter to re-inspect the determination result of whether the heavy hammer is in the state of being sucked / clamped by the lifting force;

[0047] 3. By monitoring data such as the lifting force, the elevation of the hammer bottom, and the upward displacement in real time, the key data during the heavy hammer ramming process can be quantified for automatic determination by a computer without manual intervention, which helps to achieve digital and intelligent construction and can greatly improve the standardized operation of pile foundations in group pile construction. At the same time, clarify the working conditions corresponding to different change trends of the lifting force, different values of the elevation of the hammer bottom, and different values of the upward displacement, provide a logical basis for the automatic determination of the computer, and output the corresponding treatment plan, which is convenient for the computer to automatically control the rammer equipment to construct according to the treatment plan, or for the operator to manually operate the rammer equipment or the pile foundation construction equipment for construction, with less dependence on the experience of construction personnel, and even without the need for construction personnel to be on duty;

[0048] 4. When replacing the large-sized filler, first lift the heavy hammer until the bottom elevation of the hammer just crosses the pipe wall clamping hammer layer, then swing the heavy hammer to one side and close to the wall to form a feeding space between the other opposite side of the heavy hammer and the inner wall of the retaining wall, and then put coarse aggregate into the feeding space, which can ensure that the size of the put coarse aggregate is as large as possible; then control the heavy hammer to descend and then rise slightly several times reciprocally, so that the coarse aggregate can effectively scrape and break the pipe wall clamping hammer layer adhered to the retaining wall under the drive of the friction of the heavy hammer; and, by changing the position of the feeding space, the cylindrical pipe wall clamping hammer layer can be cleaned more comprehensively, thereby effectively reducing the risk of hammer clamping in subsequent ramming. Brief Description of the Drawings

[0049] Figure 1 is a schematic flow chart of the construction method of the embodiment of the present application;

[0050] Figure 2 is a schematic diagram of the logic for judging and disposing the hammer suction / hammer clamping and the judgment scheme of the embodiment of the present application;

[0051] Figure 3 is a schematic longitudinal sectional structure diagram for disposing by putting coarse aggregate in the state of pipe wall hammer clamping of the embodiment of the present application;

[0052] Figure 4 is a schematic cross-sectional structure flow chart for disposing by putting coarse aggregate of the embodiment of the present application; a is lifting the hammer to close to the wall, b is putting coarse aggregate into the feeding space, c is lifting and lowering the hammer reciprocally to remove the local pipe wall clamping hammer layer, d is changing the position of the heavy hammer and repeating the disposal steps;

[0053] Figure 5 is a schematic structure diagram of the intelligent rammer equipment of the embodiment of the present application.

[0054] Description of the Reference Numerals in the Drawings:

[0055] 1, retaining wall;

[0056] 2, heavy hammer;

[0057] 3, enlarged head;

[0058] 4, pipe wall clamping hammer layer;

[0059] 51, feeding space; 52, coarse aggregate;

[0060] 61, chassis module; 62, support module; 63, ramming module; 64, material conveying module. Detailed Embodiments

[0061] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0062] The present application embodiment discloses an intelligent method for constructing a bottom-enlarged pile in a pipe. Figure 1 , Figure 2 and Figure 3 , which comprises the following steps:

[0063] S1. Drill a hole at the set pile position and lower the retaining wall 1 to the bearing layer, or directly press the retaining wall 1 down to the bearing layer to form a pile hole. Specifically, if a prefabricated pile is used, the retaining wall 1 is a prestressed pipe pile; if a cast-in-place pile is used, the retaining wall 1 is a steel casing; no matter what structure the retaining wall 1 adopts, the method of drilling a hole first and then lowering the pipe / pile, or lowering the pipe / pile with or without a bottom seal can be adopted.

[0064] If the post-hole forming method is adopted, during the actual construction, a bottom seal is first set at the bottom of the protective wall body 1 and pressed down to the bearing layer. After the filling material is placed, the bottom seal is broken by tamping with a heavy hammer 2. The bottom seal can be a steel plate welded on the end plate of the prefabricated pipe pile or a concrete pile tip embedded in the bottom of the prefabricated pipe pile; or, the bottom of the protective wall body 1 is not sealed and directly pressed down to the bearing layer, and then soil is taken from the hollow part of the protective wall body 1 to the bearing layer, and then the filling material is tamped.

[0065] S2. Add filler into the hollow part of the wall protection body 1, and lift the heavy hammer 2 to tamp it. Detect the lifting force of the heavy hammer 2, which is defined as F, and define the dead weight of the heavy hammer 2 as G.

[0066] S3. If the pulling force of the hammer after the heavy hammer 2 hits the filler is greater than the dead weight of the heavy hammer 2, it is determined that the heavy hammer 2 is clamped / absorbed, and one of the following methods, such as increasing the amount of filler next time, lowering the lifting height of the heavy hammer 2, and replacing the filler with larger particle size, or a combination of several methods, is adopted for disposal.

[0067] S4. Check whether the density of the enlarged head 3 formed by the tamping of the filler meets the construction standard. If the construction is qualified, proceed to the next step; otherwise, continue to put in the filler and tamp; and when checking the enlarged head 3, use one of the following methods:

[0068] (i) Lift the heavy hammer 2 to the set hammer lifting height and tamp the filling material. If the sinking amount of the heavy hammer 2 per tamping does not increase after N consecutive tampings without filling the material, the enlarged head 3 is qualified, where N ≥ 3;

[0069] (ii) Measure three-strike penetration.

[0070] S5. Pour concrete in the hollow part of the retaining wall body 1 to construct the pile body; if the retaining wall body 1 is a steel casing, the steel casing 1 can be slowly pulled out while pouring concrete during the construction of the pile body.

[0071] Based on a large amount of construction experience related to pile foundations, considering that the situation of the heavy hammer 2 being clamped is quite different in different construction stages, in order to quickly handle these clamping situations and reduce the damage to the rammer equipment or pile foundation construction equipment, the handling methods adopted should also be different.

[0072] For example, in the initial stage of construction, the heavy hammer 2 is basically in the bearing layer soil below the pile bottom when ramming the filler. At this time, during the ramming process of the heavy hammer 2, due to the influence of the groundwater pressure or the water content of the soil layer itself, the bottom end of the heavy hammer 2 enters the soft soil at the bearing layer to form a pile bottom suction hammer. The suction effect of this pile bottom suction hammer layer on the heavy hammer 2 is mainly the viscous adsorption force and vacuum adsorption force of the soft soil on the periphery of the bottom end of the heavy hammer 2. If not handled in time, the pulling force required to lift the heavy hammer 2 will become larger and larger, which will not only damage the rammer equipment, but also pose a serious safety hazard to construction workers once the steel wire rope breaks.

[0073] In the middle stage of construction, the construction of the enlarged head 3 below the pile body is basically coming to an end. At this time, the heavy hammer 2 is basically above the pile bottom when ramming the filler, that is, inside the retaining wall body 1, such as in the lower area inside the steel casing or precast pipe pile. At this time, during the ramming process of the heavy hammer 2, since there must be a certain gap between the heavy hammer 2 and the retaining wall body 1 to ensure the smoothness of the hammering, a part of the filler rammed by the heavy hammer 2 will be squeezed into this gap to form a hardening ring-shaped or tubular pipe wall clamping hammer layer 4. The clamping effect of this pipe wall clamping hammer layer 4 on the heavy hammer 2 is mainly the frictional force and the wrapping effect between the pipe wall clamping hammer layer 4 and the heavy hammer 2. If not handled in time, as the filling - ramming process continues, more and more filler enters the pipe wall clamping hammer layer 4, including some aggregates and stones mixed in the filler, which will further increase the hardness and reduce the inner diameter of the pipe wall clamping hammer layer 4. In severe cases, it will block at the pile bottom, finally resulting in the heavy hammer 2 being unable to be pulled out or unable to be smoothly hammered down, or the free-fall hammering energy of the heavy hammer 2 being weakened or even the pile exploding under the interference of the pipe wall clamping hammer layer 4, all of which will seriously affect the construction efficiency of the pile foundation. Currently, only a large-tonnage crane can be used to forcibly lift and pull the heavy hammer 2, or the pile body needs to be damaged after pulling out the pile to take out the heavy hammer 2, and this loss is immeasurable.

[0074] Therefore, for the above different construction situations, this application proposes different handling schemes for two clamping hammer situations.

[0075] Specifically, referring to Figure 1 and Figure 2, in step S3, if the detected hammer lifting force F first slowly increases and then decreases to the self-weight G of the hammer 2 within a short period of time, it is determined that the hammer 2 is in the state of the pile bottom sucking the hammer, and the disposal is carried out by increasing the filling amount of the next filling material and / or reducing the lifting height of the hammer 2.

[0076] If the detected hammer lifting force F rapidly increases to a certain range value and then decreases to the self-weight G of the hammer 2 after a certain period of time, it is determined that the hammer 2 is in the state of the pipe wall clamping the hammer, and the disposal is carried out by replacing the filling material with larger particle size and / or reducing the lifting height of the hammer 2. Among them, setting a certain range value is considered that during the process of the hammer 2 passing through the pipe wall clamping layer 4, due to the existence of aggregate or stone in the filling material, the hammer lifting force F will fluctuate. For example, when the aggregate or stone contacts and scratches the hammer 2, the hammer lifting force F will increase by a certain amount, and when these aggregate or stones roll and the contact surface with the hammer 2 decreases, the hammer lifting force F will decrease by a certain amount. Therefore, the range span when specifically taking values for this certain range value can be set according to ±1% of the self-weight G of the hammer 2. Of course, it can also be other values. The higher the required determination accuracy, the smaller the range span, and the above specific values should not be regarded as a limitation to this application. And setting a certain period of time is considered based on the fact that the pipe wall clamping layer 4 may be annular or cylindrical. During the process of the hammer 2 passing through the pipe wall clamping layer 4, the hammer lifting force F basically maintains at a relatively large value greater than the self-weight G of the hammer 2 for a certain period of time. Considering that pre-disposal is required to reduce the risk of clamping the hammer, this certain period of time can be 1s. Of course, it can also be other values. The higher the required determination accuracy, the smaller this certain period of time, and the above values should not be regarded as a limitation to this application.

[0077] Thus, by distinguishing the different characteristics of the change of the hammer lifting force F in the state of the pile bottom sucking the hammer and the state of the pipe wall clamping the hammer of the hammer 2, and taking targeted disposal measures and intervening in time, the probability of the continuous deterioration of the hammer clamping condition can be greatly reduced.

[0078] For example, when the hammer 2 is in the state of the pile bottom sucking the hammer, during the process of lifting the hammer 2, the soft soil at the bearing layer has a viscous adsorption force on the bottom of the hammer 2, so that the hammer lifting force F slowly increases as the hammer 2 is slowly lifted. When the hammer lifting force F increases to a certain value, the viscous adsorption effect of the soft soil at the bearing layer on the bottom of the hammer 2 rapidly decreases, so that the hammer 2 can be separated from the pile bottom sucking layer within a short period of time, and the hammer lifting force F returns to the self-weight G of the hammer 2. Therefore, it can be determined that the hammer 2 has experienced the state of the pile bottom sucking the hammer before. To avoid the influence of this pile bottom sucking the hammer on the subsequent ramming of the hammer 2, the filling amount of the next filling material can be increased so that the filling material can cover the pile bottom sucking layer as much as possible and inhibit the adsorption effect of the pile bottom sucking layer on the hammer 2; the lifting height of the hammer 2 can also be reduced to reduce the ramming energy of the hammer 2, thereby reducing the depth of the hammer 2 penetrating into the pile bottom sucking layer and also reducing the viscous adsorption force of the pile bottom sucking layer on the hammer 2; or both schemes can be adopted simultaneously to improve the disposal efficiency.

[0079] For another example, when the weight hammer 2 is in the state of clamping the pipe wall, during the process of lifting the weight hammer 2, the pipe wall clamping layer 4 surrounds the gap between the weight hammer 2 and the inner wall of the retaining wall body 1. Its frictional force and tightening force on the weight hammer 2 hinder the upward movement of the weight hammer 2, causing the lifting hammer pulling force F to rapidly increase to a large value after the weight hammer 2 is lifted. As the weight hammer 2 continues to be lifted, the weight hammer 2 always remains in contact with the pipe wall clamping layer 4, which causes the lifting hammer pulling force F to be maintained within a certain range value for a certain period of time. When the bottom of the weight hammer 2 gradually passes through the pipe wall clamping layer 4, the effective friction area between the two decreases and the frictional force decreases, causing the lifting hammer pulling force F to also decrease. Until the bottom of the weight hammer 2 completely passes through the pipe wall clamping layer 4, the lifting hammer pulling force F returns to the self-weight G of the weight hammer 2. Therefore, it can be determined that the weight hammer 2 has experienced the state of clamping the pipe wall before. To avoid the influence of this pipe wall clamping on the subsequent ramming of the weight hammer 2, large particle size filling materials can be replaced to scrape the pipe wall clamping layer 4 of the large particle size filling materials through the ramming of the weight hammer 2 on the large particle size filling materials, breaking or scraping off the pipe wall clamping layer 4; or the lifting height of the weight hammer 2 can be reduced and the ramming energy of the weight hammer 2 can be reduced to avoid premature hardening of the pipe wall clamping layer 4, so that part of the pipe wall clamping layer 4 falls off by itself during the subsequent ramming of the weight hammer 2; or two schemes can be adopted simultaneously to improve the disposal efficiency.

[0080] Thus, during the ramming process of the weight hammer 2, by monitoring the lifting hammer pulling force F in real time and comparing its numerical change with the self-weight G of the weight hammer 2, the possible hammer suction / clamping situation of the weight hammer 2 can be discovered in advance and disposed of in time. Moreover, according to the change trend of the lifting hammer pulling force F compared with the self-weight G of the weight hammer 2, the key data during the ramming process of the weight hammer 2 are quantified, which can be automatically judged by a computer without manual intervention, helping to achieve digital and intelligent construction, and greatly improving the pile foundation standardization operation in group pile construction. At the same time, the working conditions corresponding to different change trends of the lifting hammer pulling force F are clarified, providing a logical basis for the automatic judgment of the computer and outputting corresponding disposal schemes, facilitating the computer to automatically control the pile foundation construction equipment to construct according to the disposal scheme, or the operator to manually operate the pile foundation construction equipment for construction, with less dependence on the experience of construction personnel, and even without the need for construction personnel to be on duty. Moreover, combined with the applicant's prior pile foundation construction method based on big data, the construction method of the intelligent pipe-expanded bottom pile in this application is more prominent in terms of intelligence and more significant in economic effect.

[0081] Further, referring to Figure 1 and Figure 2 , in step S3, the hammer bottom elevation of the weight hammer 2 is also detected. If the hammer bottom elevation before lifting is lower than the pile bottom elevation and the lifting hammer pulling force F first slowly increases and then decreases to the self-weight G of the weight hammer 2 in a short time, it is determined that the weight hammer 2 is in the state of hammer suction at the pile bottom;

[0082] If the elevation of the bottom of the hammer before lifting is not lower than the elevation of the bottom of the pile and the lifting force F of the hammer rapidly increases to a certain range value and then decreases to the self-weight G of the heavy hammer 2 after a certain period of time, it is determined that the heavy hammer 2 is in the state of being clamped by the pipe wall.

[0083] The purpose of such a setting is that based on the above analysis of the causes of the hammer suction state at the bottom of the pile and the pipe wall clamping state, it can be basically determined that the hammer suction state at the bottom of the pile only occurs in the process of ramming and filling the filler in the bearing stratum below the bottom of the pile by the bottom end of the heavy hammer 2. At this time, the elevation of the bottom of the hammer before lifting the heavy hammer 2 is bound to be lower than the elevation of the bottom of the pile; while the pipe wall clamping state basically occurs in the process of ramming and filling the filler in the retaining wall 1 by the bottom of the heavy hammer 2. At this time, the elevation of the bottom of the hammer before lifting the heavy hammer 2 generally will be higher than or equal to the elevation of the bottom of the pile. After making this restriction, the judgment mechanism of the two hammer suction / clamping states can be further clarified, and the accuracy of intelligent judgment can be improved.

[0084] Of course, in the actual construction process, due to the influence of various objective and subjective factors, it may also occur that the elevation of the bottom of the hammer of the heavy hammer 2 is lower than the elevation of the bottom of the pile, but the change trend of the lifting force F conforms to the situation of the pipe wall clamping state, or other situations that may occur and are not the above two specific construction conditions. At this time, the construction personnel can manually control the pile foundation construction equipment for disposal. Therefore, the above setting is only one of the optimal embodiments of the present application and does not represent a limitation to the present application.

[0085] In addition, considering that among the three disposal methods of increasing the filling amount of the next filling material, reducing the lifting height of the heavy hammer 2, and replacing the filling material with a larger particle size in the above step S3, the disposal directions for the clamping of the heavy hammer 2 have different emphases. However, in the specific construction, after reducing the lifting height of the heavy hammer 2, the ramming energy of the heavy hammer 2 decreases, which will to a certain extent reduce the construction efficiency and affect the progress of the pile foundation construction; while the other two disposal methods have less impact on the construction progress.

[0086] For this reason, in another feasible embodiment, referring to Figure 1 and Figure 2 , in step S3, the upward displacement of the heavy hammer 2 from the start of lifting the hammer to the time when the lifting force is just equal to the self-weight of the heavy hammer 2 is also detected, that is, the upward displacement of the heavy hammer 2 from the start of lifting the hammer to the time when the heavy hammer 2 is out of the clamped state. This upward displacement can be used to characterize the degree of the heavy hammer 2 being sucked / hit by the hammer. The larger the upward displacement, the more serious the degree of the heavy hammer 2 being sucked / hit by the hammer.

[0087] When it is determined that the heavy hammer 2 is in the state of hammer suction at the bottom of the pile, if the upward displacement is not greater than the first threshold, first increase the filling amount of the next filling material and then ram. If the upward displacement of the heavy hammer 2 after continuous ramming not less than three times does not tend to zero after the disposal, then reduce the lifting height of the heavy hammer 2; among them, the first threshold is a range value, which can be 10 - 50 cm, and its value is related to the self-weight of the heavy hammer 2. The greater the self-weight of the heavy hammer 2, the larger the specific value of the first threshold can be.

[0088] If the upward displacement is greater than the first threshold, only the method of reducing the lifting height of the rammer 2 is adopted, or the method of reducing the lifting height of the rammer 2 and increasing the filling amount of the next filling material is adopted simultaneously;

[0089] Until it is determined that the rammer 2 does not suck the hammer, restore the original lifting height of the rammer 2 and the filling amount of the single filling material, and continue to feed and tamp.

[0090] When it is determined that the rammer 2 is in the state of being clamped by the pipe wall, since the bottom end of the rammer 2 is inside the retaining wall body 1 and its bottom end is basically flush with the bottom of the pipe wall clamping layer 4, the above-mentioned upward displacement can be used to represent the thickness of the pipe wall clamping layer 4. Therefore, the upward displacement can also be used to determine whether the rammer 2 sucks the hammer / clamps the hammer. When the upward displacement approaches zero, it means that there is no phenomenon of the rammer 2 sucking the hammer / clamping the hammer; when the upward displacement is greater than a certain value of zero, it means that the rammer 2 is in the state of sucking the hammer / clamping the hammer, which can be used as a determination parameter for the state of the rammer 2 sucking the hammer / clamping the hammer together with the lifting hammer tension F, and can also be used as a re-inspection parameter to re-inspect the determination result of whether the rammer 2 is in the state of sucking the hammer / clamping the hammer through the lifting hammer tension F. Thus, the determination accuracy of the construction method of the intelligent pipe-expanded bottom pile in this application for the state of the rammer 2 sucking the hammer / clamping the hammer can be significantly improved.

[0091] Therefore, when the rammer 2 is in the state of sucking the hammer at the bottom of the pile, through the setting of the first threshold, when the degree of the rammer 2 sucking the hammer is relatively light, the method of increasing the filling amount of the next filling material can be adopted first to avoid affecting the construction progress; if the degree of the rammer 2 sucking the hammer has not been significantly improved after treatment, the method of reducing the lifting height of the rammer 2 is adopted to ensure that while improving the situation of the rammer 2 sucking the hammer, the impact on the construction efficiency is minimized as much as possible.

[0092] Regarding the treatment method of replacing the large-particle-size filling material, it should be specifically stated that the proportion of the coarse aggregate 52 in the replaced large-particle-size filling material is not less than 50%, the particle size of the coarse aggregate 52 is greater than the difference between the radius of the rammer 2 and the inner wall of the retaining wall body 1 and less than or equal to the difference between the diameter of the rammer 2 and the inner wall of the retaining wall body 1, and the coarse aggregate 52 can be stones, broken concrete blocks, steel slag, construction waste, etc.

[0093] And when putting the coarse aggregate 52, referring to Figure 3 and Figure 4 , it includes the following steps:

[0094] S31. Lift the rammer 2 until the bottom elevation of the rammer just crosses the pipe wall clamping layer 4, specifically referring to when the lifting hammer tension F is just equal to the self-weight of the rammer 2, and swing the rammer 2 to one side and stick it to the wall so that a feeding space 51 is formed between the other opposite side of the rammer 2 and the inner wall of the retaining wall body 1, as Figure 4as shown in a of [reference]; then put coarse aggregate 52 into the feeding space 51 so that part of the coarse aggregate 52 stays on the upper end surface of the pipe wall clamping hammer layer 4, as Figure 4 shown in b of [reference].

[0095] S32. Control the weight hammer 2 to reset to the central position in the retaining wall body 1 or stay at the current eccentric position, and first descend and then ascend reciprocally several times with a small amplitude, so that the coarse aggregate 52 is scraped off the pipe wall clamping hammer layer 4 adhered to the inner wall of the retaining wall body 1 from top to bottom under the frictional drive of the weight hammer 2, as Figure 4 shown in c of [reference]; and if the weight hammer 2 rises and falls with a small amplitude at an eccentric position, not only can the coarse aggregate 52 be used to scrape a part of the pipe wall clamping hammer layer 4 locally, but the bottom of the weight hammer 2 itself can also scrape a part of the other side of the pipe wall clamping hammer layer 4, and the area of the pipe wall clamping hammer layer 4 broken at one time is larger. And when lifting the weight hammer 2, it is necessary to avoid that after the bottom of the weight hammer 2 is lifted too high, the coarse aggregate 52 falls from the hollow part of the pipe wall clamping hammer layer 4 and loses the breaking effect on the pipe wall clamping hammer layer 4;

[0096] If the pulling force F of the weight hammer 2 does not decrease significantly during the small-amplitude lifting and lowering process, steps S31 - S32 can be repeated, and when swinging the iron wall of the weight hammer 2, swing it in other directions to change the position of the feeding space 51 on the cross-section of the retaining wall body 1, as Figure 4 shown in d of [reference], to achieve a more comprehensive breaking effect on the pipe wall clamping hammer layer 4.

[0097] Thus, by lifting the weight hammer 2 above the pipe wall clamping hammer layer 4 and then swinging the weight hammer 2 to adhere to the wall, the feeding space 51 can be made as large as possible, and the coarse aggregate 52 placed can also be made as large as possible, at least larger than the thickness of the cylindrical pipe wall clamping hammer layer 4, so that when the weight hammer 2 descends, it can effectively scrape and break the pipe wall clamping hammer layer 4 adhered to the retaining wall body 1 by means of the rolling of the coarse aggregate 52 between the retaining wall body 1 and the weight hammer 2. And by changing the position of the feeding space 51, the cylindrical pipe wall clamping hammer layer 4 can be cleaned more comprehensively, thereby effectively reducing the risk of clamping the hammer in subsequent ramming.

[0098] In addition, with the continuous development of automated and intelligent construction methods, the accuracy requirements for some key parameters in the construction process are getting higher and higher. For example, the elevation of the hammer bottom, the upward displacement, the ramming settlement in one blow, the penetration in three blows, etc. all require data accurate to the centimeter level or millimeter level. Usually, these data are judged by the travel of the steel wire rope. Therefore, whether the steel wire rope is in a taut state is a key factor in ensuring the accuracy of the detection results.

[0099] Therefore, in step S2, the zero-point pulling force for lifting the hammer is also set according to the self-weight of the rammer 2. When the pulling force for lifting the hammer is greater than or equal to the zero-point pulling force for lifting the hammer and maintains the set time, it is determined that the steel wire rope for lifting the rammer 2 is in a taut state. Only then can the elevation and displacement of the rammer 2 be determined according to the travel of the steel wire rope. Among them, the zero-point pulling force for lifting the hammer can be set according to the self-weight of the rammer 2, such as set to 30% - 50% of the self-weight of the rammer 2, or can also be set according to the steel wire rope used. This can ensure the detection accuracy when detecting the above data each time and improve the accuracy of the detection results.

[0100] The embodiment of the present application also discloses an intelligent rammer device for implementing the above-mentioned construction method of an intelligent pipe-expanded bottom pile. Referring to Figure 2 and Figure 5 , it includes:

[0101] A chassis module 61 for carrying and moving the device.

[0102] A support module 62 for supporting and raising the hanging point of the device, which can specifically be a column or a gantry;

[0103] A ramming module 63 includes a winch, a steel wire rope, and a rammer 2. The steel wire rope is hung on the hanging point of the device formed by the support module 62 to lift and lower the rammer 2; when the steel wire rope is specifically hung, it can only be reversed and guided through a fixed pulley, or can also use a pulley block to lift the rammer 2 with less effort.

[0104] A feeding module 64 for conveying filling material into the pile hole, generally including a hopper and a belt conveyor.

[0105] A detection module for detecting the pulling force for lifting the rammer 2 when the steel wire rope lifts the rammer 2, as well as the elevation of the bottom of the rammer 2 and the upward displacement of the rammer 2.

[0106] A control module for controlling the operation of the ramming module 63 and the feeding module 64 according to the detection data of the detection module, specifically for implementing the control logic of the above-mentioned construction method of an intelligent pipe-expanded bottom pile; and / or, for the operator to manually control the operation of the ramming module 63 and the feeding module 64.

[0107] A data storage module for storing construction data, as well as the detection data and control data of the detection module and the control module. Among them, the construction data includes but is not limited to the standard amount of single automatic filling, the lifting height of the hammer, the total number of ramming times of the rammer until the filling material is compacted to meet the standard, as well as the filling times, the total filling amount, the construction duration, etc.; the detection data includes but is not limited to the self-weight of the rammer, the pulling force for lifting the hammer, the elevation of the bottom of the hammer, the elevation of the bottom of the pile, the upward displacement, the ramming settlement amount in one strike, the penetration degree in three strikes, etc.; the control data includes but is not limited to the control data generated when implementing the construction method of an intelligent pipe-expanded bottom pile. And

[0108] A communication module, configured to upload the data stored in the data storage module to a remote monitoring platform.

[0109] The detection module includes a pressure sensor for detecting the lifting weight of the wire rope when lifting the weight 2 and a counter for detecting the travel of the wire rope.

[0110] Moreover, the zero-point pulling force for lifting the weight is set according to the self-weight of the weight 2. Only when the detected value of the pressure sensor is greater than or equal to the zero-point pulling force for lifting the weight and maintains the set time (such as 300 milliseconds), after it is determined that the wire rope is in a taut state, the detection data of the counter becomes effective.

[0111] Unless otherwise defined, the technical terms or scientific terms used in this application shall have the ordinary meanings understood by those of ordinary skill in the art to which this application pertains. The terms "first", "second", "third" and similar terms used in the specification and claims of this application do not denote any order, quantity or importance, but are only used to distinguish different components. The terms "a" or "an" and similar terms do not denote a quantity limitation, but mean that there is at least one. The terms "including" or "comprising" and similar terms are intended to mean that the elements or items appearing before "including" or "comprising" cover the elements or items listed after "including" or "comprising" and their equivalents, and do not exclude other elements or items. The terms "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0112] The above are all preferred embodiments of this application. Without limiting the protection scope of this application accordingly, therefore: All equivalent changes made according to the structure, shape and principle of this application shall be covered within the protection scope of this application.

Claims

1. A construction method for an intelligent in-pipe under-reamed pile, characterized in that It includes the following steps: S1. Drill a hole at the set pile position and lower the retaining wall body to the bearing stratum, or directly press the retaining wall body to the bearing stratum to form a pile hole; S2. Put filling materials into the hollow part of the retaining wall body, lift the heavy hammer for ramming, and detect the lifting force of the heavy hammer; S3. If the lifting force of the heavy hammer is greater than the self-weight of the heavy hammer after ramming the filling materials, it is determined that the heavy hammer is jammed / sucked by the hammer. One or a combination of the following methods is adopted for disposal: increasing the filling amount of the next filling material, reducing the lifting height of the heavy hammer, and replacing the filling material with a larger particle size; S4. Check whether the compactness of the enlarged head formed by ramming the filling materials meets the construction standard. If the construction is qualified, proceed to the next step; otherwise, continue to put in filling materials and ram them; S5. Pour concrete in the hollow part of the retaining wall body to construct the pile body; In step S3, if the lifting force of the heavy hammer first increases slowly and then decreases to the self-weight of the heavy hammer in a short time, it is determined that the heavy hammer is in the state of being sucked by the pile bottom, and the method of increasing the filling amount of the next filling material and / or reducing the lifting height of the heavy hammer is adopted for disposal; If the lifting force of the heavy hammer rapidly increases to a certain range value and then decreases to the self-weight of the heavy hammer after a certain time, it is determined that the heavy hammer is in the state of being jammed by the pipe wall, and the method of replacing the filling material with a larger particle size and / or reducing the lifting height of the heavy hammer is adopted for disposal.

2. The construction method of an intelligent pipe-expanded bottom pile according to claim 1, wherein, In step S3, the bottom elevation of the heavy hammer is also detected. If the bottom elevation of the heavy hammer is lower than the bottom elevation of the pile before lifting the hammer and the lifting force of the heavy hammer first increases slowly and then decreases to the self-weight of the heavy hammer in a short time, it is determined that the heavy hammer is in the state of being sucked by the pile bottom; If the bottom elevation of the heavy hammer is not lower than the bottom elevation of the pile before lifting the hammer and the lifting force of the heavy hammer rapidly increases to a certain range value and then decreases to the self-weight of the heavy hammer after a certain time, it is determined that the heavy hammer is in the state of being jammed by the pipe wall.

3. The construction method of an intelligent pipe-expanded bottom pile according to claim 1, characterized in that, In step S3, the upward displacement of the heavy hammer from the start of lifting the hammer to the time when the lifting force of the heavy hammer is just equal to the self-weight of the heavy hammer is detected; When it is determined that the heavy hammer is in the state of being sucked by the pile bottom, if the upward displacement is not greater than the first threshold value, first increase the filling amount of the next filling material and then ram. If the upward displacement of the heavy hammer after continuous ramming for no less than three times does not approach zero after disposal, reduce the lifting height of the heavy hammer; If the upward displacement is greater than the first threshold value, only adopt the disposal method of reducing the lifting height of the heavy hammer or simultaneously adopt the disposal methods of reducing the lifting height of the heavy hammer and increasing the filling amount of the next filling material; Until it is determined that the heavy hammer is not sucked by the hammer, restore the original lifting height of the heavy hammer and the filling amount of the single filling material, and continue to put in materials and ram.

4. The construction method of an intelligent pipe-expanded bottom pile according to claim 2, characterized in that, In step S3, the proportion of coarse aggregate in the replaced filling material with a larger particle size is not less than 50%, and the particle size of the coarse aggregate is greater than the difference between the radius of the heavy hammer and the inner wall of the retaining wall body and less than or equal to the difference between the diameter of the heavy hammer and the inner wall of the retaining wall body.

5. The construction method of an intelligent in-pipe under-reamed pile according to claim 4, characterized in that In step S3, when putting in the coarse aggregate, it includes the following steps: S31. Lift the heavy hammer until the bottom elevation of the hammer just crosses the pipe wall jamming layer, swing the heavy hammer to one side to form a feeding space between the other opposite side of the heavy hammer and the inner wall of the retaining wall body, and then put the coarse aggregate into the feeding space; S32. Control the heavy hammer to reciprocate up and down slightly for several times to make the coarse aggregate scrape off the pipe wall jamming layer adhered to the inner wall of the retaining wall body under the drive of the friction of the heavy hammer.

6. The construction method of an intelligent pipe-expanded bottom pile according to claim 1, characterized in that, In step S2, the zero-point tension of the hammer lifting is set according to the self-weight of the weight hammer. When the hammer lifting tension is greater than or equal to the zero-point tension of the hammer lifting and maintains for a set time, it is determined that the steel wire rope for lifting the weight hammer is in a taut state, and then the elevation and displacement of the weight hammer can be determined according to the walking amount of the steel wire rope.

7. The construction method of an intelligent pipe-expanded bottom pile according to claim 1, characterized in that, In step S1, if a precast pile is constructed, the retaining wall body is a prestressed pipe pile; if a cast-in-situ pile is constructed, the retaining wall body is a steel casing. When driving the pile, a bottom seal is set at the bottom of the retaining wall body and pressed down to the bearing stratum, and after filling material is put in, the bottom seal is broken by ramming with the weight hammer; or, the bottom of the retaining wall body is not sealed and directly pressed down to the bearing stratum, then the soil is taken from the hollow part of the retaining wall body to the bearing stratum, and then filling and ramming are carried out.

8. The construction method of an intelligent in-pipe under-reamed pile according to claim 1, characterized in that, In step S4, one of the following methods is used to inspect the enlarged head: (1) Lift the weight hammer to a set hammer lifting height and ram the filling material. If the sinking amount of the weight hammer does not increase after continuous ramming N times without filling material, the construction of the enlarged head is qualified, where N≥3; (2) Measure the penetration per blow.

9. An intelligent rammer device for implementing a construction method of an intelligent pipe-expanded bottom pile as described in any one of claims 1-8, characterized in that, It includes: A chassis module for carrying and moving the equipment; A support module for supporting and lifting the hanging point of the equipment; A ramming module including a winch, a steel wire rope and a weight hammer. The steel wire rope is hung on the hanging point of the equipment formed by the support module to lift and lower the weight hammer; A material conveying module for conveying filling material into the pile hole; A detection module for detecting the hammer lifting tension when the steel wire rope lifts the weight hammer, as well as the elevation of the bottom of the weight hammer and the upward displacement of the weight hammer; And According to the change trend of the hammer lifting tension compared with the self-weight of the weight hammer, the key data in the process of ramming the weight hammer are quantified for automatic determination by a computer; clarify the working conditions corresponding to different change trends of the hammer lifting tension, provide a logical basis for the automatic determination of the computer, and output the corresponding treatment plan, so as to facilitate the computer to automatically control the pile foundation construction equipment to construct according to the treatment plan, or the operator manually operates the pile foundation construction equipment for construction.

10. An intelligent rammer device according to claim 9, characterized in that, It also includes: A data storage module for storing construction data and the detection data of the detection module; A communication module for uploading the data stored in the data storage module to a remote monitoring platform.

11. An intelligent rammer device according to claim 9, characterized in that, The detection module includes a pressure sensor for detecting the hammer lifting tension when the steel wire rope lifts the weight hammer and a counter for detecting the walking amount of the steel wire rope; The zero-point tension of the hammer lifting is set according to the self-weight of the weight hammer. Only when the detected value of the pressure sensor is greater than or equal to the zero-point tension of the hammer lifting and maintains for a set time, after it is determined that the steel wire rope is in a taut state, the detection data of the counter becomes effective.

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