阅读说明：本技术 一种水平地基置换结合桩体顶升加固纠偏的方法 (Horizontal foundation replacement and pile body jacking reinforcement deviation rectifying method ) 是由 郤保平 何水鑫 贾国平 吴阳春 李晓雪 成泽鹏 杨欣欣 辛国旭 董赟盛 于 2019-10-16 设计创作，主要内容包括：一种水平地基置换结合桩体顶升加固纠偏的方法,属于地基加固纠偏领域,可解决在整体性差、破碎松散地基上的古建筑地基加固及纠偏的问题,采用在建筑四周开挖导坑,在导坑中水平开掘建筑的原有地基,替换为预制钢筋混凝土板,最后采用对拉螺杆将多块预制钢筋混凝土板拉紧,在其四周设置圈梁。最终将软弱破碎的原有地基替换为一块完整的钢筋混凝土板地基。在新地基正下方设置千斤顶逐段向下顶进钢管桩至稳定岩层,纠正不均匀沉降和建筑物倾斜,最终完成对发生不均匀沉降的倾斜古建筑的地基置换加固与纠偏。本发明施工速度快,所需人力物力少,对上部建筑扰动更小更加安全,最终替换完毕后的钢筋混凝土板地基的整体性、稳定性都高于其他置换方法。(A horizontal foundation replacement and pile body jacking combined reinforcement deviation rectifying method belongs to the field of foundation reinforcement deviation rectifying, and can solve the problems of reinforcing and deviation rectifying of ancient building foundations with poor integrity and broken loose foundations. And finally replacing the soft and broken original foundation with a complete reinforced concrete slab foundation. And arranging a jack under the new foundation to jack the steel pipe pile section by section downwards to a stable rock stratum, correcting uneven settlement and building inclination, and finally completing foundation replacement reinforcement and correction of the inclined ancient building with uneven settlement. The method has the advantages of high construction speed, less manpower and material resources required, less disturbance to the upper building and higher safety, and the integrity and the stability of the reinforced concrete slab foundation after the final replacement are higher than those of other replacement methods.)

1. A horizontal foundation replacement combined pile body jacking reinforcing deviation rectifying method is characterized in that: the method comprises the following steps:

firstly, surveying and preparing prefabricated parts before construction: performing drilling investigation near a building (1) to be reinforced, determining soil quality grade and hydrological information around the building, judging the crushing degree of a foundation to be reinforced by combining a building construction process and a construction age, measuring the size of the building, judging the bearing capacity of the foundation, and determining the excavation area and depth of a pilot tunnel; preparing a prefabricated reinforced concrete slab (4) and a horizontal rectangular drilling machine (5); the prefabricated reinforced concrete slab (4) is provided with pre-buried hooks (10) and through holes, and the length and width of the prefabricated reinforced concrete slab (4) are larger than those of foundation excavation;

secondly, temporarily supporting the upper building, excavating pilot pits around the building, assembling a horizontal rectangular drilling machine (5) on the pilot pit on one side, and placing a precast reinforced concrete plate (4) on the pilot pit on the other side opposite to the pilot pit on which the horizontal rectangular drilling machine (5) is placed;

thirdly, replacing the foundation, namely averagely dividing the foundation into seven parts, numbering 6, 2, 4, 1, 5, 3 and 7 from left to right, and replacing the foundation according to the numbering sequence of 1, 2, 3, 4, 5, 6 and 7, wherein the replacement method comprises the following steps: the method comprises the following steps of starting tunneling, connecting a horizontal rectangular drilling machine (5) with a precast reinforced concrete plate (4) after the horizontal rectangular drilling machine (5) tunnels the original foundation (2), dragging the horizontal rectangular drilling machine (5) and the precast concrete plate (4) back along a tunneling channel through hydraulic power to ensure that the precast reinforced concrete plate (4) just replaces an excavated part, namely completing foundation replacement operation at one position, and repeating the steps to replace the foundations at other positions;

fourthly, after replacement is finished, penetrating and tensioning the opposite-pulling screw rods (7) along the through holes of the prefabricated reinforced concrete slab (4), arranging ring beams (6) on the periphery of the prefabricated reinforced concrete slab (4) to form a complete reinforced concrete slab foundation as a new foundation, wherein the length and the width of the formed new foundation are respectively 1.2 times of those of the original foundation;

fifthly, continuously downwards excavating one side of the reinforced concrete slab foundation to a reinforcement point right below, arranging a hydraulic jack (11), downwards jacking a steel pipe pile (12) by adopting a section-by-section jacking method until the steel pipe pile is in a stable rock stratum, jacking the buildings at the upper part of the foundation together after pile body jacking at a plurality of positions is completed, and correcting uneven settlement and building inclination;

and sixthly, backfilling and compacting the soil body, dismantling the temporary support of the building to be reinforced, recovering the original ground, and completing horizontal replacement and reinforcement of the broken foundation.

Technical Field

The invention belongs to the technical field of foundation reinforcement and deviation correction, and particularly relates to a horizontal foundation replacement and pile body jacking reinforcement and deviation correction method.

Background

In the history of more than five thousand years in China, countless craftsmen leave ancient buildings which can fully reflect building level, wind, soil, human emotion and religion etiquette on the vast land in China. The ancient buildings are invaluable treasures in China, but are limited by the backward construction level of ancient times, and a great number of ancient buildings are directly built on the simply-treated crushed stone rammed earth foundation, but the simply-treated foundation is poor in integrity and bearing capacity. Under the disturbance of underground seepage, weathering, stratum movement and surrounding building construction, the foundation is stressed unevenly, and even settlement occurs in the past, so that the upper building is cracked, inclined and even collapsed, which brings great problems to the protection of ancient buildings. In view of the current situation, it is necessary to take effective foundation reinforcement measures to prevent uneven settlement, or to reinforce and correct the settlement of the building having uneven settlement.

At present, the reinforcement method aiming at the soft foundation mainly comprises the following steps: 1. the building jacking reinforcing method is that the pile body is jacked downwards to stable rock stratum in foundation and foundation bearing position by means of the dead weight of the upper building as the counter force of the support and the building is jacked. The multiple pile bodies provide supporting force for the building and correct the uneven settlement which occurs, so that the upper building reaches a stable state. The method is mainly used for buildings with good integrity and good foundation bearing capacity, and the foundations of most of ancient buildings are loose and broken and difficult to provide stable supporting points when pushed downwards, so that the ideal reinforcing and deviation rectifying effect is difficult to achieve. 2. The horizontal foundation replacement method generally includes excavating a construction pilot tunnel on the side surface of a building to expose the original foundation, and then jacking a steel pipe or a prefabricated box girder in the horizontal direction. And after the steel pipe is jacked, filling soil expansion materials into the pipe, and synchronously pulling out the steel pipe to finish foundation replacement. The method is simple but has limited effect, uneven settlement still possibly occurs after the treated foundation is disturbed again or the ground water is eroded, and the uneven settlement which occurs is difficult to correct by adopting the method; when the hand-digging box girder jacking method is adopted, the jacking speed is slow, the jacking resistance is large, and the disturbance generated during jacking construction easily causes irreversible damage to an upper building.

Disclosure of Invention

The invention provides a horizontal foundation replacement and pile body jacking combined reinforcement and deviation correction method aiming at the problems of reinforcement and deviation correction of ancient buildings on foundation with poor integrity and broken and loose foundation, which can obviously reduce the disturbance to upper buildings during construction, improve the integral stability of the foundation and correct uneven settlement.

The invention adopts the following technical scheme:

a method for reinforcing and correcting deviation by combining horizontal foundation replacement with pile body jacking comprises the steps of firstly excavating construction guide pits around a building to a target depth, then excavating one side of each guide pit to the other side through a horizontal rectangular drilling machine, connecting a prefabricated reinforced concrete plate placed in the guide pit on the other side in advance after the guide pits are communicated, and dragging the reinforced concrete plate back to a specified position along a tunneling channel through hydraulic power, so that foundation replacement construction of one position is completed. Through the foundation replacement construction of rationally arranging a plurality of positions, the replacement construction of whole foundation is finally accomplished. The prefabricated reinforced concrete plates are tensioned by the opposite tension screw rods to form a whole, and the ring beams are arranged around the prefabricated reinforced concrete plates, so that the original foundation with poor integrity and loose and broken foundation can be replaced by a whole reinforced concrete plate, and the purpose of foundation replacement is achieved. And finally, correcting the settlement or the inclination of the building according to the conventional pile jacking method according to the concrete condition of the inclination or the settlement of the building after the foundation replacement is finished, and specifically comprising the following steps:

firstly, surveying and preparing prefabricated parts before construction: performing drilling investigation near a building to be reinforced, determining soil quality grade and hydrological information around the building, judging the crushing degree of a foundation to be reinforced by combining a building construction process and the age, measuring the size of the building, judging the bearing capacity of the foundation, and determining the excavation area and depth of a pilot tunnel; preparing a prefabricated reinforced concrete slab and a horizontal rectangular drilling machine; the prefabricated reinforced concrete slab is provided with pre-buried hooks and through holes, and the length and width of the prefabricated reinforced concrete slab are larger than those of foundation excavation;

secondly, temporarily supporting an upper building, excavating pilot pits around the building, assembling a horizontal rectangular drilling machine on the pilot pit on one side, and placing a prefabricated reinforced concrete plate on the pilot pit on the other side opposite to the pilot pit on which the horizontal rectangular drilling machine is placed;

thirdly, replacing the foundation, namely averagely dividing the foundation into seven parts, numbering 6, 2, 4, 1, 5, 3 and 7 from left to right, and replacing the foundation according to the numbering sequence of 1, 2, 3, 4, 5, 6 and 7, wherein the replacement method comprises the following steps: the excavation is started, after the horizontal rectangular drilling machine excavates the original foundation, the horizontal rectangular drilling machine is connected with the prefabricated reinforced concrete slab, the horizontal rectangular drilling machine and the prefabricated concrete slab are pulled back along the excavation channel through hydraulic power, the prefabricated reinforced concrete slab is ensured to just replace the excavated part, namely, the foundation replacement operation of one position is completed, and the steps are repeated to replace the foundations of the other positions;

fourthly, after replacement is finished, penetrating and tensioning the counter-pulling screw rods along the through holes of the prefabricated reinforced concrete slab, and arranging ring beams around the prefabricated reinforced concrete slab to form a complete reinforced concrete slab foundation as a new foundation, wherein the length and the width of the new foundation are respectively 1.2 times of those of the original foundation;

fifthly, continuously downwards excavating one side of the reinforced concrete slab foundation to a reinforcement point right below, arranging a hydraulic jack, downwards jacking the steel pipe pile by adopting a section-by-section jacking method until the steel pipe pile is in a stable rock stratum, jacking the buildings at the upper part of the foundation together after the pile bodies at multiple positions are jacked, and correcting uneven settlement and building inclination;

and sixthly, backfilling and compacting the soil body, removing the temporary support of the building, recovering the original ground, and finishing horizontal replacement reinforcement of the broken foundation and correction of building settlement.

The invention has the following beneficial effects:

the invention adopts a horizontal rectangular drilling machine to sequentially excavate the soft foundation at a target depth, and drags the prefabricated reinforced concrete slab back into the soft foundation from the other side along the excavated channel. And (3) replacing the original foundation with a reinforced concrete slab foundation and then correcting the uneven settlement by adopting a steel pipe pile jacking method. The whole horizontal foundation replacement process makes full use of the self structural stability of the soil body and the structure of the horizontal rectangular drilling machine to maintain the stability of the channel excavated in the broken foundation, so that the defects that the original horizontal foundation replacement method is complicated in construction, secondary settlement is easily caused, and the vibration generated by jacking construction is large in disturbance to the upper building are overcome at one stroke, and meanwhile, the defect that the building jacking method is difficult to effectively apply in the broken and loose foundation is overcome.

1. The invention finally forms a whole plate-shaped foundation, the stress area of the whole plate-shaped foundation is larger than that of the pile body used in the integral jacking reinforcement method of the building, the whole plate-shaped foundation can bear larger upper pressure, and the horizontal sliding resistance capability is stronger.

2. The invention adopts the prefabricated reinforced concrete slab as the replacement foundation, the construction speed of the dragging and replacing foundation is high, and the bearing capacity can be recovered without grouting or filling expansion materials immediately after the dragging and replacing is finished, thereby avoiding the further softening and instability of the original broken foundation caused by using cement grout (or other reinforcing grout).

3. The invention has small disturbance to the upper buildings, does not cause large-scale unloading in the whole foundation replacement construction process, has small change of the stress state of the building, and is more stable and safer compared with other construction methods.

4. The invention finally forms a whole reinforced concrete slab foundation which has strong anti-seepage and anti-softening capability, and compared with other methods, the invention can effectively reduce the influence of underground seepage on buildings.

5. The invention finally forms a whole reinforced concrete slab foundation, and can correct the uneven settlement or building inclination by adopting a pile body jacking method.

Drawings

FIG. 1 is a schematic view of a pilot excavation structure;

FIG. 2 is a schematic side view of a pilot tunnel excavation;

FIG. 3 is a schematic view of a top view structure of pit guiding excavation;

FIG. 4 is a single location foundation replacement flow diagram;

FIG. 5 is a single position foundation replacement completion diagram;

FIG. 6 is a schematic view of the foundation after replacement;

FIG. 7 is a schematic side view of the foundation after completion of replacement;

FIG. 8 is a schematic top view of the foundation after replacement;

FIG. 9 is a schematic view of a prefabricated reinforced concrete slab connected by means of counter-pulling screws;

FIG. 10 is a schematic diagram of a side view structure of a prefabricated reinforced concrete slab connected by counter-pulling screws;

FIG. 11 is a schematic view of a prefabricated reinforced concrete slab connected by means of counter-pulling screws;

FIG. 12 is a front view of the ring beam;

FIG. 13 is a side view of the collar beam mounting arrangement;

FIG. 14 is a schematic top view of the ring beam installation;

FIG. 15 is a schematic view of a pile jacking deviation rectifying structure;

FIG. 16 is a schematic diagram of a side view of a pile body jacking deviation rectifying structure;

FIG. 17 is a schematic diagram of a jacking, deviation-correcting and overhead-view structure of a pile body;

FIG. 18 is a schematic view of a foundation reinforcement and deviation correction completion main structure;

FIG. 19 is a schematic view of a side view of a foundation reinforcement and deviation rectification completion structure;

FIG. 20 is a schematic view of a top view of a foundation reinforcement and deviation correction completion structure;

wherein: 1-inclined buildings to be reinforced; 2-original foundation; 3-earth surface soil mass; 4-prefabricating a reinforced concrete slab; 5-horizontal rectangular drilling machine; 6-ring beam; 7-oppositely pulling the screw rod; 8-bolt; 9-a gasket; 10-pre-burying hooks; 11-hydraulic jack; 12-steel pipe pile.

Detailed Description

The invention is further explained with reference to the accompanying drawings.

A horizontal foundation replacement combined pile body jacking reinforcement deviation rectifying method comprises the following steps:

firstly, surveying and preparing prefabricated parts before construction: performing drilling investigation near a building to be reinforced, determining soil quality grade and hydrological information around the building, judging the crushing degree of a foundation to be reinforced by combining a building construction process and the age, measuring the size of the building, judging the bearing capacity of the foundation, and determining the excavation area and depth of a pilot tunnel; preparing a prefabricated reinforced concrete slab and a horizontal rectangular drilling machine; the prefabricated reinforced concrete slab is provided with pre-buried hooks and through holes, and the length and width of the prefabricated reinforced concrete slab are larger than those of foundation excavation;

secondly, temporarily supporting an upper building, excavating pilot pits around the building, assembling a horizontal rectangular drilling machine on the pilot pit on one side, and placing a prefabricated reinforced concrete plate on the pilot pit on the other side opposite to the pilot pit on which the horizontal rectangular drilling machine is placed;

thirdly, replacing the foundation, namely averagely dividing the foundation into seven parts, numbering 6, 2, 4, 1, 5, 3 and 7 from left to right, and replacing the foundation according to the numbering sequence of 1, 2, 3, 4, 5, 6 and 7, wherein the replacement method comprises the following steps: the excavation is started, after the horizontal rectangular drilling machine excavates the original foundation, the horizontal rectangular drilling machine is connected with the prefabricated reinforced concrete slab, the horizontal rectangular drilling machine and the prefabricated concrete slab are pulled back along the excavation channel through hydraulic power, the prefabricated reinforced concrete slab is ensured to just replace the excavated part, namely, the foundation replacement operation of one position is completed, and the steps are repeated to replace the foundations of the other positions;

fourthly, after replacement is finished, penetrating and tensioning the counter-pulling screw rods along the through holes of the prefabricated reinforced concrete slab, and arranging ring beams around the prefabricated reinforced concrete slab to form a complete reinforced concrete slab foundation as a new foundation, wherein the length and the width of the new foundation are respectively 1.2 times of those of the original foundation;

fifthly, continuously downwards excavating one side of the reinforced concrete slab foundation to a reinforcement point right below, arranging a hydraulic jack, downwards jacking the steel pipe pile by adopting a section-by-section jacking method until the steel pipe pile is in a stable rock stratum, jacking the buildings at the upper part of the foundation together after the pile bodies at multiple positions are jacked, and correcting uneven settlement and building inclination;

and sixthly, backfilling and compacting the soil body, dismantling the temporary support of the building to be reinforced, recovering the original ground, and completing horizontal replacement and reinforcement of the broken foundation.