阅读说明：本技术 一种适用于水下灌注桩的被动加固施工方法 (Passive reinforcing construction method suitable for underwater cast-in-place pile ) 是由 巨宏亮 唐小军 任培涛 于海洲 程为 刘志平 徐安东 任学志 尤春颖 王雷 于 2021-09-14 设计创作，主要内容包括：本发明提供了一种适用于水下灌注桩的被动加固施工方法,包括以下步骤：S1:根据设计要求确定灌注桩在水底具体施工位置；S2：采用高压旋喷注浆技术围绕灌注桩中心施工位置圆周方向均匀施工多个高压旋喷桩,高压旋喷桩2穿过水底淤泥层设置,每相邻两个所述高压旋喷桩间留有距离,高压旋喷桩中心至灌注桩中心距离L为：L＝R+r。本发明所述的水下灌注桩被动加固施工方法作业简单,使用比较方便、安全,多个高压旋喷桩对淤泥层也就是灌注桩施工位置提前进行加固,同时对后续钻孔灌注过程中灌注桩的施工进行了加固,整体结构简单受力明确。(The invention provides a passive reinforcement construction method suitable for an underwater cast-in-place pile, which comprises the following steps of: s1, determining the concrete construction position of the cast-in-place pile at the water bottom according to the design requirements; s2: adopt high-pressure jet grouting technique around bored concrete pile center construction position circumferencial direction evenly construct a plurality of high-pressure jet grouting piles, high-pressure jet grouting pile 2 passes submarine silt layer setting, every adjacent two leave the distance between the high-pressure jet grouting pile, high-pressure jet grouting pile center is to bored concrete pile center distance L be: l ═ R + R. The passive reinforcing construction method for the underwater cast-in-place pile is simple in operation, convenient and safe to use, the multiple high-pressure jet grouting piles reinforce a sludge layer, namely the construction position of the cast-in-place pile in advance, the construction of the cast-in-place pile in the subsequent drilling and pouring process is reinforced, and the overall structure is simple and is stressed clearly.)

1. A passive reinforcement construction method suitable for an underwater cast-in-place pile is characterized by comprising the following steps: the method comprises the following steps:

s1, determining the concrete construction position of the cast-in-place pile (1) at the water bottom according to the design requirement;

s2: adopt high-pressure jet grouting technique around bored concrete pile (1) central construction position circumferencial direction evenly construct a plurality of high-pressure jet grouting pile (2), high-pressure jet grouting pile (2) pass submarine silt layer setting, every adjacent two leave the distance between high-pressure jet grouting pile (2), high-pressure jet grouting pile (2) center is to bored concrete pile (1) central distance L:

L＝R+r；

wherein: r: radius of the cast-in-place pile:

r: and (4) the radius of the high-pressure jet grouting pile.

2. The passive reinforcement construction method suitable for the underwater cast-in-place pile according to claim 1, characterized in that: the length of the high-pressure jet grouting pile (2) is the distance from the foundation bearing platform bottom elevation to the rock surface elevation corresponding to the cast-in-place pile (1).

3. The passive reinforcement construction method suitable for the underwater cast-in-place pile according to claim 1, characterized in that: the radius r of the high-pressure jet grouting pile (2) is as follows: r/3 is more than or equal to R and less than or equal to R/2.

4. The passive reinforcement construction method suitable for the underwater cast-in-place pile according to claim 1, characterized in that: the number n of the high-pressure jet grouting piles (2) is as follows:

n＝ROUND(3π/[4arcsin[r/(R+r)]]。

5. the passive reinforcement construction method suitable for the underwater cast-in-place pile according to claim 1, characterized in that: the high-pressure rotary jet grouting pile (2) is a single-pipe high-pressure rotary jet grouting pile.

6. The passive reinforcement construction method suitable for the underwater cast-in-place pile according to claim 5, characterized in that: the water-cement ratio of the slurry for construction of the high-pressure jet grouting pile (2) is 0.9: 1-0.7: 1, the grouting pressure is 28-33mpa, the lifting speed of a jet grouting head is 18-20cm per minute, and the rotating speed of the jet grouting head is 25R per minute.

Technical Field

The invention belongs to the field of civil engineering, and particularly relates to a passive reinforcement construction method suitable for an underwater cast-in-place pile.

Background

In the cast-in-situ bored pile construction process, a temporary platform is usually erected, a pile casing is arranged for positioning protection, and a drilling machine drills into a hole, and due to the influence of adverse factors such as a typhoon high-incidence area and a silt geological layer thickness, the traditional construction method has the following problems when the cast-in-situ bored pile is constructed, particularly when geological exploration is unclear, the drilling depth is large and the like:

firstly, the method comprises the following steps: the method occupies more construction materials, has poor pile forming quality of the drilled pile, is easy to cause quality accidents such as deviation, pile breakage and the like, and has great waste.

Secondly, the method comprises the following steps: for the construction of cast-in-situ bored piles under the geological condition of an ultra-thick silt layer, the arrangement applicability of the steel pile casing is not high because the pile casing needs to penetrate the silt layer in different lengths of 20-45m, the material consumption is too large, the cost is high, the inserting and driving are difficult, and particularly, the inserting and driving operation is unsafe due to large wind power in coastal areas. Meanwhile, the long length of the protection tube easily causes quality accidents such as inclined holes and the like.

Disclosure of Invention

In view of the above, the invention aims to provide a passive reinforcement construction method suitable for an underwater cast-in-place pile, so as to solve the problems of low quality, easy occurrence of construction quality accidents such as inclined holes, broken piles and the like in underwater cast-in-place pile construction under the unfavorable construction conditions such as a typhoon high-rise area, thick silt geological layer, deep and large drilled pile holes and the like, and solve the problems of large waste, high cost, difficult and unsafe construction of inserting and driving a steel pile casing, small action effect and the like.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a passive reinforcement construction method suitable for an underwater cast-in-place pile comprises the following steps:

s1, determining the concrete construction position of the cast-in-place pile at the water bottom according to the design requirements;

s2: adopt high-pressure jet grouting technique around bored concrete pile center construction position circumferencial direction evenly construct a plurality of high-pressure jet grouting piles, high-pressure jet grouting pile 2 passes submarine silt layer setting, every adjacent two leave the distance between the high-pressure jet grouting pile, high-pressure jet grouting pile center is to bored concrete pile center distance L be:

L＝R+r；

wherein: r: radius of the cast-in-place pile:

r: and (4) the radius of the high-pressure jet grouting pile.

Further, the length of the high-pressure rotary jet grouting pile is the distance from the elevation of the corresponding foundation bearing platform bottom of the cast-in-place pile to the elevation of the rock surface.

Further, the radius r of the high-pressure jet grouting pile is as follows: r/3 is more than or equal to R and less than or equal to R/2.

Further, the number n of the high-pressure jet grouting piles is as follows: n is ROUND (3 pi/[ 4arcsin [ R/(R + R) ] ].

Furthermore, the high-pressure jet grouting pile is a single-pipe high-pressure jet grouting pile.

Further, the water-cement ratio of the slurry for high-pressure jet grouting pile construction is 0.9: 1-0.7: 1, the grouting pressure is 28-33mpa, the lifting speed of a jet nozzle is 18-20cm per minute, and the rotating speed of the jet nozzle is 25R per minute.

Compared with the prior art, the passive reinforcement construction method applicable to the underwater cast-in-place pile has the following advantages:

1. the operation is simple, and it is more convenient, safe to use, and a plurality of high pressure jet grouting piles are consolidated in advance to silt layer also be bored concrete pile construction position, have consolidated the construction of bored concrete pile in the filling process of follow-up drilling simultaneously, and overall structure is simple the atress clearly and definitely.

2. The construction process is optimized, the use of the steel casing during the construction of the cast-in-situ bored pile is omitted, the working efficiency is improved, the construction safety is improved, the construction flow is simplified, and the use of steel of the casing is saved.

3. The method avoids the situation of large waste caused by quality accidents of poor pile forming quality, easy deviation, pile breakage and the like of the cast-in-situ bored pile in the conventional construction method, solves the problem of delayed construction period caused by the quality problem of the cast-in-situ bored pile, and has good economic benefit and social benefit.

4. The safety risk is less in the work progress, and the operation space demand is not big.

5. It is possible to construct bored piles of different diameters for different geological formations.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic diagram of a passive reinforcement construction method for an underwater cast-in-place pile according to this embodiment;

description of reference numerals:

1-filling a pile; 2-high pressure jet grouting pile.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

A passive reinforcement construction method suitable for an underwater cast-in-place pile comprises the following steps:

s1, determining the concrete construction position of the cast-in-place pile 1 at the water bottom according to the design requirements;

s2: adopt high-pressure jet grouting technique around 1 central construction position circumferencial direction of bored concrete pile evenly to construct a plurality of high-pressure jet grouting pile 2, high-pressure jet grouting pile 2 is single tubular method high-pressure jet grouting pile, and high-pressure jet grouting pile 2 passes submarine silt layer setting, and is less than submarine rock face elevation setting at the bottom of high-pressure jet grouting pile 2, every adjacent two leave the distance between high-pressure jet grouting pile 2, and high-pressure jet grouting pile 2 center is to 1 central distance L of bored concrete pile:

L＝R+r；

wherein: r: radius of cast-in-place pile 1:

r: and (3) the radius of the high-pressure jet grouting pile 2.

After the construction of the high-pressure jet grouting pile 2 is completed, the construction of a drilled pile can be carried out, namely the construction of the cast-in-place pile 1 can be carried out. After the construction of the cast-in-place pile 1 is completed, the positional relation between the cast-in-place pile 1 and the high-pressure jet grouting pile 2 is shown in figure 1, the plurality of high-pressure jet grouting piles 2 are uniformly arranged around the cast-in-place pile 1, the outer circumferential surface of the cast-in-place pile 1 is tangent to the outer circumferential surface of the high-pressure jet grouting pile 2, a sludge layer at the construction position of the cast-in-place pile 1 is reinforced through the plurality of high-pressure jet grouting piles 2, the construction reliability of the cast-in-place pile on water is improved, and the cast-in-place pile 1 is protected at the same time, so that the cast-in-place pile drilling construction can be carried out subsequently without using a steel casing, the quality problems that the steel casing is too long, inclined holes and the like are caused are solved, the construction quality of the cast-in-place pile is ensured, the construction flow of the cast-in-place pile is simplified, the use of the steel casing is saved, and the construction safety is ensured. Meanwhile, after the construction of the cast-in-place pile 1 is completed, the high-pressure jet grouting pile 2 has a reinforcing function, and the fixity and the supporting stability of the cast-in-place pile 1 are ensured.

In this embodiment, the length of the high-pressure jet grouting pile 2 is the distance from the elevation of the foundation bearing platform corresponding to the cast-in-place pile 1 to the elevation of the rock surface.

In this embodiment, the radius r of the high-pressure jet grouting pile 2 is as follows: r/3 is more than or equal to R and less than or equal to R/2.

In this embodiment, the number n of the high-pressure jet grouting piles 2 is as follows: the design ensures that the size of a central angle beta corresponding to a gap between two adjacent high-pressure jet grouting piles 2 is about one third of the central angle alpha corresponding to one high-pressure jet grouting pile 2 relative to the construction circumference where the high-pressure jet grouting pile is located, so that on one hand, constructors can conveniently and quickly determine the number of the high-pressure jet grouting piles, and on the other hand, the reinforcement of the high-pressure jet grouting pile 2 to the cast-in-place pile 1 and a bottom silt layer is ensured.

In the embodiment, the high-pressure jet grouting pile 2 is a single-pipe high-pressure jet grouting pile, the water-cement ratio of the slurry for high-pressure jet grouting construction is 0.9: 1-0.7: 1, the grouting pressure is guaranteed to be 28-33mpa during construction, the lifting speed of a jet head of a high-pressure jet grouting drilling machine is 18-20cm per minute, and the rotating speed of the jet head is 25R per minute.

Taking an example of the construction of the cast-in-place pile with the diameter of 1400mm, firstly, determining the underwater construction position of the cast-in-place pile with the diameter of 1400mm, determining the central position of the cast-in-place pile, then selecting the radius of the high-pressure jet grouting pile to be 300mm, positioning the center of the high-pressure jet grouting pile on the circumference which takes the center of the cast-in-place pile as the center of a circle and has the radius of 1000mm, determining the construction quantity of the high-pressure rotary spraying piles to be 8 according to a formula n-ROUND (3 pi/[ 4arcsin [ R/(R + R) ]), positioning a high-pressure rotary spraying drilling machine on a construction platform, constructing the 8 high-pressure rotary spraying piles after measurement and positioning, enclosing the 8 high-pressure rotary spraying piles to form a circular area with the diameter of 1400, the area is a cast-in-place pile construction area, the sludge layer is reinforced by 8 high-pressure jet grouting piles, the cast-in-place pile construction is protected, and drilled piles can be constructed after the high-pressure jet grouting pile construction is completed, namely the cast-in-place pile construction is carried out.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.