阅读说明：本技术 大直径海上风电嵌岩单桩开挖方法 (Large-diameter offshore wind power rock-socketed single pile excavation method ) 是由 卢文波 陈明 李康贵 王高辉 严鹏 于 2020-06-11 设计创作，主要内容包括：本发明公开了一种大直径海上风电嵌岩单桩开挖方法,包括如下步骤：沉放导井护筒；采用石油钻机通过导井护筒开挖导井；采用地质钻钻设2～3圈主爆孔和1圈轮廓爆破孔,下放套管护孔；安装专用CO<Sub>2</Sub>相变膨胀致裂管,主爆孔内分段安装,轮廓爆破孔内连续安装；连接爆破网路；下放嵌岩单桩钢护筒；吸除导井护筒与嵌岩单桩钢护筒之间的淤泥和风化砂；拔出导井护筒和钻孔套管；水下清渣；灌注混凝土形成嵌岩单桩基础。本发明将导井机械开挖和CO<Sub>2</Sub>膨胀破岩扩挖相结合,突破利用2～4m直径石油钻机和普通地质钻机完成8～10m及以上直径海上嵌岩单桩基础开挖技术难题,CO<Sub>2</Sub>相变产生的膨胀压力可控,爆炸冲击波和振动速度小,经济环保。(The invention discloses a large-diameter offshore wind power rock-socketed single pile excavation method, which comprises the following steps: sinking a guide well casing; excavating a pilot shaft through a pilot shaft protecting cylinder by adopting an oil drilling machine; drilling 2-3 circles of main blast holes and 1 circle of outline blast holes by using a geological drill, and lowering a casing protection hole; CO special for installation 2 The phase change expansion cracking tube is installed in the main blast hole in a segmented mode, and the contour blast hole is continuously installed in the contour blast hole; connecting the blasting network; putting down the rock-socketed single-pile steel casing; absorbing and removing sludge and weathered sand between the guide well casing and the rock-socketed single-pile steel casing; pulling out the guide well protection sleeve and the drilling sleeve; underwater slag removal; and pouring concrete to form a rock-socketed single-pile foundation. The invention leads the well to be mechanically excavated and CO 2 The expansion rock breaking and the expanding excavation are combined, and the process of completing the opening of the marine rock-socketed single pile foundation with the diameter of 8-10 m or more by using an oil drilling machine with the diameter of 2-4 m and a common geological drilling machine is broken throughDifficult technical problem of digging, CO 2 The expansion pressure generated by phase change is controllable, the explosion shock wave and the vibration speed are low, and the method is economical and environment-friendly.)

1. The large-diameter offshore wind power rock-socketed single pile excavation method is characterized by comprising the following steps of: excavating and CO (carbon monoxide) by adopting well guiding machinery₂Expansion rock breaking and expanding excavation are combined: firstly, excavating a pilot well by using an oil drilling machine with the diameter of 2.0-4.0 m for subsequent CO₂The phase change expansion rock breaking creates a face, the diameter of a pilot shaft excavated by an oil drilling machine is 1.2-3.0 m, and the ultra depth of the pilot shaft reaches 0.10-0.15 time of the depth of a pile foundation; the method comprises the following steps:

1) sinking the guide well casing to a specified depth;

2) adjusting the position of a working platform of the oil drilling machine, and excavating a pilot shaft to a designed depth through a pilot shaft pile casing;

3) drilling 2-3 circles of main blast holes and 1 circle of outline blast holes on the periphery of a pilot shaft by using a geological drilling machine, and then lowering a casing protection hole;

4) special CO is installed in the main blast hole sleeve in a subsection manner₂The phase-change expansion cracking tube is well blocked, and special CO is continuously installed in the contour blasting hole sleeve₂A phase change expansion fracturing pipe;

5) the main blasting holes are symmetrically blasted from top to bottom and the contour blasting holes are blasted simultaneously;

6) putting down the rock-socketed single-pile steel casing;

7) covering layer sludge and weathered sand between the guide well casing and the rock-socketed single-pile steel casing are sucked and removed;

8) pulling out the guide well protection sleeve and the drilling sleeve;

9) grabbing slag by using underwater slag removing equipment;

10) and pouring concrete to form a rock-socketed single-pile foundation.

2. The excavation method for the large-diameter offshore wind power socketed single pile according to claim 1, characterized in that: and (3) the center line of the pilot well, the center line of the main blast hole and the center line of the outline blast hole in the step 3) are collinear.

3. The excavation method for the large-diameter offshore wind power socketed single pile according to claim 1 or 2, characterized in that: the total number of the main explosion holes in the step 3) is 2-3 circles; the distance between the innermost ring of the main blasting holes and the pilot shaft is 0.8-1.5 m, the distance between two adjacent rings of the main blasting holes is 0.8-1.5 m, the distance between the profile blasting holes and the outermost ring of the main blasting holes is 0.8-1.5 m, the profile blasting holes exceed the designed diameter of the pile foundation by 0.2-0.8 m, and the drilling distance is 0.8-1.5 m.

4. The excavation method for the large-diameter offshore wind power socketed single pile according to claim 1 or 2, characterized in that: the special CO for sectional installation in the main explosion hole in the step 4)₂A phase change expansion cracking tube without special CO₂The interval section of the phase change expansion cracking pipe is provided with an electric igniter with a time delay function and is blocked by using a water absorption expansion rubber material, the length of the interval section is 30-80 cm, and the interval section is specially used for continuously installing in the outline blasting holeCO₂The phase change expands the fractured pipe.

5. The excavation method for the large-diameter offshore wind power socketed single pile according to claim 3, characterized in that: the special CO for sectional installation in the main explosion hole in the step 4)₂A phase change expansion cracking tube without special CO₂The interval section of the phase change expansion cracking pipe is provided with an electric igniter with a time delay function and is blocked by using a water absorption expansion rubber material, the length of the interval section is 30-80 cm, and special CO is continuously installed in the outline blasting hole₂The phase change expands the fractured pipe.

6. The excavation method for the large-diameter offshore wind power socketed single pile according to claim 1, 2 or 5, characterized in that: and in the step 5), the main blast holes are detonated and broken in a layered manner in circles, 1-2 pairs of blast holes are detonated symmetrically each time, the single blast holes are detonated sequentially from top to bottom, the detonation delay time is more than 30ms, and the contour blast holes are detonated simultaneously by adopting a controlled blasting technology.

7. The excavation method for the large-diameter offshore wind power socketed single pile according to claim 1, 2 or 5, characterized in that: the diameters of the main blast hole and the profile blast hole in the step 4) are 110-150 mm, and the special CO is used₂The diameter of the phase change expansion cracking tube is more than 80 mm.

Technical Field

The invention belongs to the technical field of engineering blasting, and particularly relates to a large-diameter offshore wind power rock-socketed single-pile excavation method.

Background

With the continuous development of social economy, people have an increasing demand for energy, especially clean energy. The offshore wind power generation has the advantages of high wind speed, long effective power generation time, no land occupation and the like, is very suitable for large-scale development, and is very suitable for offshore wind power generation under the condition of long coastline and rich offshore wind energy resources in China, thereby providing favorable congenital conditions for offshore wind power generation. The offshore wind farm fan foundation mainly comprises a large-diameter rock-socketed single-pile foundation, a grouped-pile rock-socketed foundation, a suction cylinder type foundation, a gravity type foundation and the like, wherein the large-diameter rock-socketed single-pile foundation is advantageous in terms of simple and convenient construction and simple structure, but the application of the large-diameter rock-socketed single-pile foundation is limited due to the problems that the offshore wind-free construction window period is short, a large-diameter drilling machine is difficult to be in place in time and the like.

In order to ensure that the large-diameter rock-socketed single-pile foundation is safely and reliably applied to a rock-based seabed, the prior technical scheme mainly comprises three schemes, namely a 'pile sinking-drilling-pile sinking' scheme, namely, drilling construction is carried out after pile sinking is carried out for the first time, and then secondary pile sinking is carried out, such as a rock-socketed single-pile foundation construction process disclosed by CN 106088140A, CN 104032765A; the other is a 'pile sinking-drilling-grouting' scheme, namely, firstly sinking the pile to a set depth, then performing drilling construction, then pouring high-strength grouting body or marine concrete, enhancing the firmness of the steel pipe single pile embedded in the rock foundation seabed, and improving the horizontal bearing capacity and the anti-overturning capacity, such as the rock-embedded single pile foundation construction process disclosed in CN 106759449A, CN 105862905A, CN 110241731A; and thirdly, a drilling-grouting-anchoring scheme is adopted, namely, a hole is drilled in a steel pipe single pile, concrete is poured to form a cast-in-place pile, an anchor rod is inserted into the cast-in-place pile and is embedded and fixed in middle and weak weathered rocks, the construction quality of the rock-socketed single pile foundation is further improved, and the rock-socketed construction risk is reduced, for example, the composite rock-socketed single pile foundation construction process disclosed in CN 105297765A. The former two schemes rely on a large-diameter drilling machine, and the construction cost is high; the third scheme has complex construction procedure and inconvenient operation, and the foundation of the wind farm on shallow sea is mainly a strong and medium weathered rock without using an anchor rod to insert the rock into the medium and weak weathered rock. In order to simplify the excavation procedure of the underwater pile foundation and improve the construction efficiency, a new excavation method of the underwater pile foundation needs to be provided, which is used for offshore wind power plant construction.

Disclosure of Invention

The invention aims to provide a large-diameter marine wind power rock-socketed single pile excavation method which can be used for underwater pile foundation excavation construction of projects such as a marine wind power plant and a sea-crossing bridge, so that the technical problem of excavation of a large-diameter marine rock-socketed single pile foundation in the construction of the marine wind power plant is effectively solved, and the construction efficiency is improved.

In order to achieve the purpose, the invention provides a large-diameter offshore wind power rock-socketed single-pile excavation method which adopts petroleum drilling machine mechanical excavation and CO₂The combination of expansion rock breaking and expanding excavation, the diameter of an oil drilling machine is 2.0-4.0 m, the diameter of a guide shaft for excavation is 1.2-3.0 m, the ultra-deep depth of the guide shaft reaches 0.10-0.15 times of the depth of a pile foundation, and the method comprises the following steps:

1) sinking the guide well casing to a specified depth; 2) adjusting the position of a working platform of the oil drilling machine, and excavating a pilot shaft to a designed depth through a pilot shaft pile casing; 3) drilling 2-3 circles of main blast holes and 1 circle of outline blast holes on the periphery of a pilot shaft by using a geological drilling machine, and then lowering a casing protection hole; 4) special CO is installed in the main blast hole sleeve in a subsection manner₂The phase-change expansion cracking tube is well blocked, and special CO is continuously installed in the contour blasting hole sleeve₂A phase change expansion fracturing pipe; 5) the main blasting holes are symmetrically blasted from top to bottom and the contour blasting holes are blasted simultaneously; 6) putting down the rock-socketed single-pile steel casing; 7) covering layer sludge and weathered sand between the guide well casing and the rock-socketed single-pile steel casing are sucked and removed; 8) pulling out the guide well protection sleeve and the drilling sleeve; 9) grabbing slag by using underwater slag removing equipment; 10) and pouring concrete to form a rock-socketed single-pile foundation.

Preferably, the centerline of the pilot hole, the centerline of the main blast hole and the centerline of the profile blast hole in the step 3) are collinear.

Further, the total number of the main explosion holes in the step 3) is 2-3 circles; the distance between the innermost ring of the main blasting holes and the pilot shaft is 0.8-1.5 m, the distance between two adjacent rings of the main blasting holes is 0.8-1.5 m, the distance between the profile blasting holes and the outermost ring of the main blasting holes is 0.8-1.5 m, the profile blasting holes exceed the designed diameter of the pile foundation by 0.2-0.8 m, and the drilling distance is 0.8-1.5 m.

Further, the special CO is installed in the main blast hole in a segmented mode in the step 4)₂A phase change expansion cracking tube without special CO₂The interval section of the phase change expansion cracking pipe is provided with an electric igniter with a time delay function and is blocked by using a water absorption expansion rubber material, the length of the interval section is 30-80 cm, and special CO is continuously installed in the outline blasting hole₂The phase change expands the fractured pipe.

Furthermore, in the step 5), the main blast holes are detonated and broken in a layered manner in circles, 1-2 pairs of blast holes are detonated symmetrically each time, the single blast holes are detonated sequentially from top to bottom, the detonation delay time is more than 30ms, and the contour blast holes are detonated simultaneously by adopting a controlled blasting technology.

Furthermore, the diameters of the main blast hole and the profile blast hole in the step 4) are 110-150 mm, and the special CO is used₂The diameter of the phase change expansion cracking tube is more than 80 mm.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the invention utilizes the well-guiding machinery to excavate and CO₂The excavation method combining expansion rock breaking and expanding excavation breaks through the technical problem that an oil drilling machine with the diameter of 2-4 m and a common geological drilling machine are used for completing excavation of marine rock-socketed single-pile foundations with the diameter of 8-10 m or more, the dependence on a large-diameter drilling machine is avoided, the construction period can be effectively shortened, and the construction efficiency is improved. By using CO₂The expansion pressure generated during phase change is controllable, the rock breaking effect is good, the large block rate is low, the delayed detonation through the main blasting hole produces the explosion shock wave with low vibration speed, and the contour blasting hole adopts the controlled blasting technology, so that the forming effect of the marine rock-socketed single-pile foundation is good. The blasting process does not generate harmful substances, and is safe and environment-friendly.

Drawings

FIG. 1 shows the CO specially used in the main explosion hole₂The installation schematic diagram of the phase change expansion cracking pipe;

FIG. 2 is a wheelSpecial CO in contour blasting hole₂The installation schematic diagram of the phase change expansion cracking pipe;

FIG. 3 is a schematic diagram of a pilot hole, main blasthole and profile blasthole distribution.

₂In the figure: 1-a blocking section, 2-a special CO phase change expansion cracking tube, 3-a water absorption expansion rubber material, 4-an electric igniter, _{1 2 3}5-pilot well, 6-main blast hole, 7-profile blast hole; r-pilot well radius, R-inner ring main explosive hole distribution radius, R-outer ring main explosive hole distribution radius ₄The distribution radius, R-profile blast hole distribution radius.

Detailed Description

The technical solutions in the embodiments of the present invention are 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 embodiments.

All embodiments that can be obtained by a person skilled in the art based on the embodiments of the present invention without making any inventive work belong to the protection scope of the present invention.

A wind power plant fan foundation on a certain sea adopts a large-diameter rock-socketed single-pile foundation, the design diameter of a pile foundation is 9.0m, the design depth is 20.0m, 2 circles of main blasting holes are drilled, 1 circle of outline blasting holes are drilled, and the excavation of the large-diameter rock-socketed single-pile foundation comprises the following steps:

1) sinking the guide well casing to a specified position by adopting a vibration hammer and a high-energy hydraulic impact hammer;

2) adjusting the position of a working platform of the oil drilling machine, drilling downwards along the central line of the guide well casing, wherein the drilling depth exceeds the design depth of a pile foundation by 2.5m, and the drilled guide well has the radius of 5R₁Is 1.2 m;

3) the geological drilling machine is replaced by a geological drilling machine, 2 circles of main blast holes 6 and 1 circle of outline blast holes 7 are drilled on the periphery of a pilot shaft 5, the diameters of the main blast holes 6 and the outline blast holes 7 are 140mm, and the special CO is used₂The diameter of the phase-change expansion cracking tube 2 is 110mm, and the distribution radius R of the main explosion hole of the inner ring₂2.5m, the distribution radius R of the main explosion hole of the outer ring₃3.7m, the profile blastholes 7 have a radius R₄Is 4.7 m;

4) special CO is installed in the main explosion hole 6 sleeve in a subsection manner₂Phase change expansion cracking tube 2 without installation of special CO₂The interval section of the phase-change expansion cracking pipe 2 is 60cm in length, an electric igniter 4 with a time delay function is installed at the interval section and is blocked by using a water-absorbing expansion rubber material 3, and special CO is continuously installed in a casing pipe of a profile blast hole 7₂The phase-change expansion cracking tube 2 is plugged by graded sand at the tops of the main blast hole 6 and the outline blast hole 7, and the length of a plugging section 1 is 3.0 m;

5) connecting the blasting network, when the water-swelling rubber material 3 absorbs water and swells to form a pressure plug, sequentially detonating a main blast hole 6 and a contour blast hole 7 from inside to outside, and arranging two adjacent sections of special CO through an electric igniter 4 with a time delay function₂The detonation delay time of the phase-change expansion fracturing pipe 2 is 50ms, 2 pairs of blast holes are detonated symmetrically each time, and the contour blast holes 7 are detonated simultaneously after the main blast holes 6 are detonated;

6) sinking the rock-socketed single-pile steel casing to the excavation depth;

7) covering layer sludge and weathered sand between the guide well casing and the rock-socketed single-pile steel casing are sucked and removed;

8) pulling out the guide well protection sleeve and the drilling sleeve;

9) grabbing slag by using underwater slag removing equipment;

10) and pouring concrete into the foundation pit to form a large-diameter rock-socketed single-pile foundation.