CH713870B1 - Combined foundation of a carbonated DSM pile and a ventable tubular pile and their construction process. - Google Patents

Abstract

The present invention relates to a combined formation of a carbonated DSM pile and a ventable tubular pile (10) and their construction method and belongs to the field of foundation treatment for civil engineering. Given the shortcomings and problems of existing solidification technologies and MgO carbonation strengthening processes for soft and weak deep foundation composite piles, a combined foundation of a carbonized DSM pile and a ventable tubular pile (CMP) (10) with high bearing capacity, high construction efficiency, become more reliable Quality, low carbon dioxide emissions and good environmental friendliness and their construction process provided. The combined formation of a carbonated DSM pile and a ventable tubular pile (10) consists of a carbonated MgO cement DSM pile (15) and a ventable tubular pile (10), which is a ventable tubular pile (10) within the carbonated MgO cement DSM pile (15) is integrated. This fulfills the requirement to consolidate the soft and weak creation and recovery of carbon dioxide resources.

Description

description

Field of the Invention The present invention relates to a combined foundation of a carbonated DSM pile (DSM: Deep Soil Mixing, deep soil mortar) and a ventilated tubular pile and their construction methods and belongs to the field of foundation treatment for civil engineering.

BACKGROUND ART In existing civil engineering works, reinforcement treatment of deep soft ground foundations with low strength, strong compressibility and low permeability is usually necessary, and as a usual foundation treatment process, usually a dynamic compaction process, a soil replacement process, a cement-lime -Mixing method, a reinforced concrete pile and a site bored pile can be used. The dynamic compaction process is not suitable for muddy, soft soil with a high water content due to the large construction noise and small scope of application, while the soil replacement process only applies to shallow foundations due to the high workload and the high costs. Thanks to its high construction speed, low disruption and low costs, the cement-lime mixing process is widely used.However, due to the limited reinforcement depth, such a process can be expected to have a low load-bearing capacity and strength as well as a quality that is difficult to control, which sometimes makes the construction work difficult is to be fulfilled. Despite the high strength and rigidity, a reinforced concrete pile causes high costs and when the maximum load capacity of the composite pile is reached, the surrounding floor is already damaged, so that the pile cannot fully develop its strength and is therefore not very economical. When building an on-site bored pile, Drill hole and constriction collapse easily, whereby even erosion of the concrete by underground water is to be expected. Therefore, scientific researchers are actively looking for a new construction method and stabilizing material to improve the impact of foundation reinforcement treatment.

The technical regulation for reinforced composite piles JCJ / T 327-2014 proposes, by combining two or three of the piles bulk piles, flexible piles (e.g. DSM piles) and rigid piles (e.g. prefabricated reinforced concrete piles or in-situ concrete piles) a combined foundation for treatment to produce soft soil. Numerous patents are currently available on composite pile foundations, such as: construction method for a composite pile (application number CN 201 410 088 076.4 / publication number CN 103 821 138 A), construction method for a composite pile with a core of high strength (application number CN 2015 10 504 437.3 / publication number CN 105 113 498 A), construction method for a reinforced composite pile with an ultra-high load capacity (application number CN 2015 10 098 526.2A / publication number CN 104 674 801 A), construction method for a multi-reinforced composite pile (application number CN 2016 10 079 641.X / publication number CN 105 649 053 A), composite pile with a protective layer of high durability and its manufacturing and construction process (application number CN 2008 10 118 790.8A / publication number CN 101 343 871 A), combined foundation of aerated concrete piles of large grain size and sand core piles as well as the associated treatment process (application number CN 2014 10 155 063. 4 / publication number CN 103 938 618 A), integrated composite pile made of pile floor and concrete as well as the associated construction method (application number CN 2016 10 027 425.2 / publication number CN 105 532 264 A) and a reinforced concrete composite pile and its manufacturing facility and manufacturing process (application number CN 2014 10 453 494.9A / publication number CN 105 464 072 B), whereby such composite pile foundations have unique advantages over simple piles, whereby, for example, a combined sand pile foundation is generally used to reinforce a sand and mud foundation and increase the load-bearing capacity and reduce the reduction and can prevent fluidization of the ground, while reinforced composite piles made of DSM piles and reinforced concrete piles absorb the load to a large extent both by fully unfolding the high load-bearing capacity of the reinforced concrete piles and also by the DSM piles the load on the surrounding ground of the pile le transfer and significantly reduce construction costs. However, with such composite piles, the piles on the outer circumference largely consist of cement / lime DSM piles, which are similar to the reinforced concrete piles and site bored piles described above and have slow starch growth, with the main material used as stabilizing material being a high level of production Energy consumption, large carbon dioxide emissions and serious pollution.

In addition, the inventor proposed to strengthen a soft and weak foundation by a carbonation DSM method using MgO and an overall carbonation method, and applied for a number of patents that are characterized by the following similarities and advantageous effects: an active one Oxide is used as a soil stabilizer and carbon dioxide is introduced for carbonation in order to quickly stabilize soft and weak soil. Compared to cement-stabilized soil or conventional DSM processes, such processes are characterized by rapid consolidation, high strength and good environmental friendliness and correspond to the development trend of environmentally friendly construction work in civil engineering. However, such patents also have corresponding disadvantages, for example carbonation stabilization processes for the soil and associated equipment (application number CN 2010 10 604 013.1A / publication number CN102102360A), treatment system and associated method for consolidating a soft soil foundation by means of heat from the industrial exhaust gases (application number CN 2013 10 122 135.0A / publication number CN 103 147 434 A) and treatment system for

CH 713 870 B1

Consolidation of a foundation and manufacturing process of carbonated piles (application number CN 2014 10 203 978.8 / publication number CN 103 981 854 A) are part of the carbonation DSM process and during the construction process the DSM piles have a limited depth and it is difficult to meet the load capacity requirement is expected, whereby carbon dioxide gas can easily escape along the mixing shaft and thus cause secondary pollution, whereby in addition to a high requirement for foaming agents for carbon dioxide foam and their stabilization time, the water content and the porosity of natural building ground is increased and an obvious solidification is hardly to be expected is, in particular with natural foundations with a high water content, the consolidation effect is significantly impaired. Also include carbonation consolidation processes by replacing a base layer of a soft ground foundation (application number CN 2014 10 272 957.1 / publication number CN 104 018 485 A) and site carbonation consolidation processes for a soft and weak shallow foundation (application number CN 2015 10 348 797.9 / publication number CN 104 912 055 B) for the treatment of a shallow foundation, in which the depth of consolidation is limited and an uneven lowering can easily occur, so that it is difficult to meet the consolidation requirements for deep-lying soft and weak subsoil, whereby there is also a large-scale exchange with a mixture of different grain sizes, which increases the workload and the construction costs of the foundation treatment and reduces the construction efficiency.

In view of the disadvantages and problems with existing consolidation technologies and MgO carbonation consolidation methods for composite piles of soft and weak deep foundations, and taking into account the situation of the rapid development of civil engineering in China and the advantages of the two consolidation technologies, it has become an important topic to combine a new type Foundation with interaction between piles and floor, coordinated increased load capacity, high building efficiency, low carbon dioxide emissions and good environmental friendliness.

DISCLOSURE OF THE INVENTION In view of the disadvantages of the above combined foundation and the carbonation-consolidation process, the present invention has for its object to provide a combined foundation of a carbonated DSM pile and a ventilated tubular pile (CMP) with high load capacity, high construction efficiency, Reliable quality, low carbon dioxide emissions and good environmental friendliness, as well as their construction methods to meet the requirement to solidify soft and weak deep foundations and utilization of carbon dioxide resources. According to the invention the object is achieved by a combined foundation of a carbonated DSMP pile and a ventilated tubular pile, which consists of a carbonated MgO cement DSM pile and a ventilated tubular pile, which integrates ventilated tubular pile within the carbonated MgO cement DSMP pile is. In other words, the ventilated tubular pile is located within the carbonated MgO cement DSM pile and is combined with it.

It is further provided that the MgO cement in the carbonated MgO cement DSM pile is a mixture of active MgO and quicklime, a mixture of active MgO and cement or a mixture of active MgO, quicklime and cement is.

In addition, the present invention also discloses that the ventilable tubular pile is a prefabricated reinforced concrete pile.

In addition, a construction method for the combined foundation of a carbonated DSM pile and a ventilated tubular pile is disclosed, which comprises the following steps:

a. Flattening the construction area, attaching a mixing pile machine, aligning the boring bar and the spiral drilling head of the pile machine perpendicular to an intended pile position of the natural foundation,

b. Switching the pile machine into a penetration state until the twist drill head rotates to the intended depth of the natural foundation, the natural foundation being cut by the helical turret and broken and mixed by the mixing blade,

c. Switching the pile machine into a lifting state, spraying MgO cement with simultaneous mixing and lifting, which completes a preliminary formation of an MgO cement DSM pile,

d. Lowering and raising the drill head again in accordance with steps b and c, re-mixing the MgO cement DSM pile until MgO cement is evenly dispersed in the MgO cement DSM pile,

e. Driving a ventilated pipe pile vertically into the MgO cement DSM pile before the cement floor has hardened,

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f. Driving a sealing hood into the uppermost area of the MgO cement DSM pile and the ventilable tubular pile, inserting a ventilation pipe over the sealing hood into the ventilable tubular pile, the vent pipe being connected to a carbon dioxide storage container at the end projecting from the tubular pile, whereby a pressure control valve is provided on the ventilation pipe,

G. Open the pressure control valve and adjust the aeration pressure so that carbon dioxide gas is diffused into the MgO-cement DSM pile body via the ventilated tubular pile, whereby a carbonated MgO-cement DSM pile is generated by venting and carbonating the MgO-cement DSM pile body and the combined one Foundation is completed from a carbonated DSM pile and a ventilated tubular pile.

It is preferably provided that the boring bar of the pile machine is hollow in its upper region and solid in its lower area, a spiral drilling head being provided on the lowest area of the boring bar of the pile machine, to the upper area of which a mixing blade is attached, which an upper mixing wing and a lower mixing wing, between which powder spray holes and mud spray holes are provided, which are arranged offset from one another, wherein a mud spray tube is also fastened within the boring bar of the pile machine, which is tightly connected to the mud spray holes, the upper mixing wing and the lower Mixing blades can have the same or opposite mixing direction.

It is preferably provided that the MgO cement is a powder or sludge, the powder being sprayed out of the powder spray holes and the sludge out of the sludge spraying holes, the spraying out of MgO cement in the form of powder or sludge in Dependence on the water content of the natural foundation is determined, the MgO cement with a water content of less than 10% in the form of sludge, with a water content of more than 20% in the form of powder and with a water content between 10% and 20% optionally sprayed out simultaneously in the form of powder and sludge.

Preferably, the MgO cement DSM pile has a diameter of 500 to 2000 mm and the ventilated tubular pile has an outside diameter of 300 to 1000 mm.

It is also disclosed in the present invention that the ventilable tubular pile is pressed hydraulically or by ramming into the MgO cement DSM pile body and the length of the ventilable tubular pile is not less than the pile body length of the MgO cement DSM pile , with a length of the ventilable tubular pile that is greater than the pile body length of the MgO cement DSM pile, MgO cement-stabilized soil or concrete is filled into the ventilable tubular pile until it is flush with the underside of the MgO cement Closes the DSM pile.

It is also disclosed that the sealing hood is made of hard plastic or stainless steel and has an inner diameter that is equal to or larger than the outer diameter of the MgO cement DSM pile body, the depth of the side wall of the sealing hood being between 100 and 1000 mm , In other words, the cover area of the sealing hood is equal to or larger than the cross-sectional area of the MgO cement DSM pile body.

Finally, it is disclosed that in step g the aeration pressure is not less than 200 kPa and the aeration and carbonation time is determined depending on the property of the soil, the aeration and carbonation time for sandy soil between 3.0 and 6.0 h, in powdery soil between 6.0 and 12.0 h and in clay between 8.0 and 12.0 h.

Using the configuration disclosed in the present invention, a combined foundation of a carbonated DSM pile and a ventilated tubular pile with high load-bearing capacity, high construction efficiency, reliable quality, low carbon dioxide emissions and good environmental friendliness is obtained, making the requirement for consolidation softer and weak foundation and utilization of carbon dioxide resources is met, whereby specifically (1) the carbonated MgO cement DSM pile and the ventilated tubular pile load together and complement each other well in terms of flexibility and rigidity, so that the frictional force of the soil is nearby of the pile body and the pile end-resistance are fully deployed and the common load bearing contributes to an increased load capacity of a single pile, while pressing through the ventilated tubular pile for a significantly increased density of the ground between the karbona tized DSM pile and the pile body, an increased strength of the carbonated MgO cement DSM pile and the floor between piles, an improved load capacity, uniformity and stability of the combined foundation and a reduced compressibility, (2) the carbonation and reinforcement of the MgO cement DSM piles can be completed within several hours, the ventilating tubular pile being a prefabricated, hollow reinforced concrete pile, the uppermost region of which is provided with a sealing hood to prevent carbon dioxide gas from escaping along the uppermost region of the pile body avoid increasing the transfer and diffusion efficiency of carbon dioxide in the MgO cement DSM pile body

CH 713 870 B1 and to improve the uniformity of the carbonation effect, with the advantages such as simple construction work, eliminated need for long-term maintenance and high construction efficiency can be achieved, (3) the ventilated tubular pile by transferring its load to the carbonated MgO cement DSM pile and the soil in the vicinity of the pile body reduces the requirement for the soil thickness of the base layer , so that even a shorter composite pile can meet the design requirement, (4) environmentally friendly active MgO is used as the main stabilizing agent for the carbonated MgO cement DSM pile and at the same time a large amount of carbon dioxide gas is absorbed during the carbonation and consolidation process, which means the disadvantages low carbon emissions, good environmental friendliness and sustainable development.

Representation of the Figure It shows:

1 is a schematic representation of a building structure for a DSM pile when building a combined foundation from a carbonated DSM pile and a ventilated tubular pile,

2 shows the combination of a ventilated pile when building a combined foundation from a carbonated DSM pile and a ventilated tubular pile in a schematic representation,

Fig. 3 shows the carbonation when building a combined foundation from a carbonated DSM pile and a ventilated tubular pile in a schematic representation, 1 for natural foundation, 2 for boring bar of the pile machine, 3 for upper mixing blades, 4 for lower mixing blades, 5 for spiral drilling heads , 6 for mud spray pipe, 7 for powder spray pipe, 8 for mud spray hole, 9 for MgO cement DSM pile, 10 for ventilated pipe pile, 11 for sealing hood, 12 for ventilation pipe, 13 for pressure control valve, 14 for carbon dioxide reservoir and 15 for carbonated MgO cement -DSM pile stand.

Concrete embodiments In the description of the present invention, the terms such as "top", "bottom", "top", "bottom", "inside," outside ", which serve to describe the direction or positional relationship, etc used in each case with respect to the illustration in the respective illustration in order only to facilitate the description of the invention. In other words, these terms neither imply nor explicitly indicate a specific positioning of the device in question, so that there is no restriction of the invention here. For a better understanding of the realization possibility, the features, the achievable task and effect, the present invention is explained in more detail below with the aid of the attached drawings.

First embodiment Fig. 3 shows a combined foundation of a carbonated DSM pile and a ventilated tubular pile, which consists of a carbonated MgO cement DSM pile 15 and a ventilated tubular pile 10, which ventilated tubular pile 10 within the carbonated MgO -Cement DSM pile 15 is integrated. The MgO cement in the carbonated MgO cement DSM pile 15 is a mixture of active MgO and quicklime, a mixture of active MgO and cement or a mixture of active MgO, quicklime and cement. The ventilated tubular pile 10 is a prefabricated reinforced concrete pile.

As can be seen from FIGS. 1, 2 and 3, the construction process for the combined foundation comprising a carbonated DSM pile and a ventilated tubular pile comprises the following steps:

a. Flattening the construction area, attaching a mixing pile machine, aligning the boring bar 2 and the spiral drilling head 5 of the pile machine perpendicular to an intended pile position of the natural foundation 1,

b. Switching the pile machine into a penetration state until the twist drill head 5 rotates to the intended depth of the natural foundation 1, the bottom of the natural foundation 1 being cut by the helical turret 5 and broken and mixed by the mixing blade,

c. Switching the pile machine into a lifting state, injection of MgO cement with simultaneous mixing and lifting, which completes a preliminary formation of an MgO cement DSM pile body 9,

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d. Lowering and raising the drill head again according to steps b and c, re-mixing the MgO cement DSM pile 9 until MgO cement is evenly dispersed in the MgO cement DSM pile 9,

e. Ramming a ventilated pipe pile 10 vertically into the MgO cement DSM pile 9 before the cement floor has hardened,

f. Ramming a sealing hood 11 into the uppermost region of the MgO cement DSM pile 9 and the ventilable tubular pile 10, inserting a ventilation tube 12 via the sealing hood 11 into the ventilating tubular pile 10, the ventilation tube 12 being at the end protruding from the tubular pile 10 a carbon dioxide reservoir 14 is connected, a pressure control valve 13 being provided on the ventilation pipe 12,

G. Opening the pressure regulating valve 13 and adjusting the ventilation pressure so that carbon dioxide gas is diffused into the pile body of the MgO cement DSM pile 9 via the ventilated tubular pile 10, wherein a carbonated MgO is produced by ventilating and carbonating the pile body of the MgO cement DSM pile 9 -Cement DSM pile 15 generated and the combined foundation of a carbonated DSM pile and a ventilated tubular pile is completed.

It is pointed in particular to Fig. 1, wherein the boring bar 2 of the pile machine is hollow in its upper region and solid in its lower region, with a spiral drill head 5 is provided on the lowest region of the boring bar 2 of the pile machine, on the latter An upper mixing blade is attached, which comprises an upper mixing blade 3 and a lower mixing blade 4, between which powder spray holes 7 and mud spray holes 8 are provided, which are arranged offset from one another, wherein a mud spray tube 6 is also fastened within the boring bar 2 of the pile machine is tightly connected to the mud spray holes 8, wherein the upper mixing wing 3 and the lower mixing wing 4 can have the same or opposite mixing direction.

The MgO cement is a powder or sludge, the powder being sprayed out of the powder spray holes 7 and the sludge out of the sludge spray holes 8, the spraying out of MgO cement in the form of powder or sludge depending on the Water content of natural foundation 1 is determined, the MgO cement with a water content of less than 10% in the form of sludge, with a water content of more than 20% in the form of powder and with a water content between 10% and 20% optionally simultaneously is sprayed out in the form of powder and mud.

The MgO cement DSM pile 9 has a diameter of 500 to 2000 mm and the ventilated tubular pile has an outer diameter of 300 to 1000 mm. The ventilable tubular pile 10 is pressed hydraulically or by ramming into the pile body of the MgO cement DSM pile 9 and the length of the ventilable tubular pile 10 is not less than the pile body length of the MgO cement DSM pile 9, with a length of ventilable tubular pile 10, which is greater than the pile body length of the MgO cement DSM pile 9, MgO cement stabilized soil or concrete is filled into the ventilable tubular pile until it is flush with the underside of the MgO cement DSM pile 9.

As can be seen from Fig. 3, the sealing hood 11 is made of hard plastic or stainless steel and has an inner diameter that is equal to or larger than the outer diameter of the MgO cement DSM pile body 9, the depth of the side wall of the Sealing hood 11 is between 100 and 1000 mm.

3, the top surface of the sealing hood 11 is equal to or larger than the cross-sectional area of the MgO cement DSM pile body 9.

In step g, the aeration pressure is not less than 200 kPa and the aeration and carbonation time is determined depending on the property of the soil, the aeration and carbonation time for sandy soil between 3.0 and 6.0 h, for powdery soil between 6.0 and 12.0 h and for sound between 8.0 and 12.0 h.

Second embodiment If the natural foundation 1 consists of sandy soil, the natural foundation has a water content of less than 10% within an area up to 5 m from the soil surface, within an area with a distance of 5 to 10 m to the soil surface a water content of 10% to 20% and at a depth greater than 10 m to the soil surface a water content of more than 20%. A powder addition amount of 10% is selected for the MgO cement and active MgO is used as a stabilizing agent, an MgO cement slurry being produced according to a mass ratio of 0.8 between water and dry powder. According to the design requirement, the diameter of the DSM pile is set to 1200 mm, the mixing depth to 10 m, the outer diameter of the ventilated tubular pile 10 to 400 mm and the length of a single ventilated tubular pile 10 to 10 m.

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a. Aligning the boring bar 2 and the spiral boring head 5 of the pile machine perpendicular to an intended pile position of the natural foundation 1,

b. Switching the pile machine into a penetration state until the spiral drilling head 5 penetrates rotatingly to a depth of 10 m below the ground surface, the sandy soil being cut by the spiral rotating head 5 and mixed by the mixing blade,

c. Switching the pile machine into a lifting state, spraying MgO cement powder by means of a dry spraying process while simultaneously mixing and lifting at a depth of greater than 10 m to the ground surface, spraying MgO cement using a slurry spraying process and powder spraying process within an area at a distance of up to 5 m to the ground surface, which completes a preliminary formation of an MgO cement DSM pile body 9,

d. Lowering and raising the drill head again according to steps b and c, re-mixing the MgO cement DSM pile 9 until MgO cement is evenly distributed in the MgO cement DSM pile 9,

e. Ramming a first ventilated tubular pile 10 vertically into the body of the MgO cement DSMP pile 9 by means of a vibrating ramming method,

f. Ramming a stainless steel sealing hood 11 into the uppermost region of the MgO cement DSM pile 9 and the ventilable tubular pile 10, the sealing hood 11 having a diameter of 1200 mm and a side wall height of 800 mm, and inserting a ventilation tube 12 into the ventilable one Tube pile 10,

G. Open the pressure regulating valve 13 and set the ventilation pressure to 200 kPa so that carbon dioxide gas is diffused into the pile body of the MgO cement DSM pile 9 via the ventilable tubular pile 9, with ventilation and carbonation of the pile body of the MgO cement DSM pile body 9 A carbonated MgO cement DSM pile 15 is generated after aeration for 4.5 h and the combined foundation of a carbonated DSM pile and a ventilated tubular pile is finished.

Third embodiment If the natural foundation 1 consists of powdery soil, the natural foundation has a water content of less than 10% within an area up to 3 m from the soil surface, within an area with a distance of 3 to 8 m to the soil surface has a water content of 10% to 20% and at a depth greater than 8 m to the soil surface a water content of more than 20%. A powder addition amount of 10% is selected for the MgO cement and a mixture of active MgO and lime is used in a mixing ratio of 1: 1, whereby according to a mass ratio of 0.8 between water and dry powder, an MgO cement Sludge is produced. According to the design requirement, the diameter of the DSM pile is set to 1400 mm, the mixing depth to 20 m, the outside diameter of the ventilated tubular pile 10 to 600 mm and the length of a single ventilated tubular pile 10 to 10 m.

a. Aligning the boring bar 2 and the spiral boring head 5 of the pile machine perpendicular to an intended pile position of the natural foundation 1,

b. Switching the pile machine into a penetration state until the spiral drilling head 5 rotates to a depth of 20 m below the ground surface, the powdery soil being cut by the spiral rotating head 5 and mixed by the mixing blade,

c. Switching the pile machine to a lifting state, spraying MgO cement powder by means of a dry spraying process while mixing and lifting at a depth of greater than 8 m to the ground surface, spraying MgO cement by means of a slurry spraying process and powder spraying process within an area at a distance of up to 3 m to the ground surface, which completes a preliminary formation of an MgO cement DSM pile body 9,

d. Lowering and raising the drill head again in accordance with steps b and c, re-mixing the MgO cement DSM pile 9 until MgO cement is evenly distributed in the MgO cement DSM pile 9,

e. Driving a first ventilable tubular pile 10 vertically into the body of the MgO cement DSMP pile 9 by means of a vibrating ramming method, lifting a second ventable tubular pile 10 when the uppermost region of the first ventilable tubular pile 10 approaches the bottom surface of the natural foundation 1, connecting the lowermost area of the second ventilable tubular pile 10 firmly with the uppermost area of the first ventilable tubular pile 10, ramming the uppermost area of the second ventilable tubular pile 10, so that the two ventilable tubular piles 10 are connected in one

CH 713 870 B1 in a state in which the MgO cement DSM pile 9 is rammed, the two ventable tubular piles 10 being connected to one another via their hollow sections,

f. Ramming a stainless steel sealing hood 11 into the uppermost area of the MgO cement DSM pile 9 and the ventilable tubular pile 10, the sealing hood 11 having a diameter of 1500 mm and a side wall height of 1000 mm, and inserting a ventilation tube 12 into the ventilable one Tube pile 10,

G. Open the pressure control valve 13 and set the ventilation pressure to 300 kPa, so that carbon dioxide gas is diffused into the pile body of the MgO cement DSM pile 9 via the ventilable tubular pile 9, ventilation and carbonization of the pile body of the MgO cement DSM pile body 9 A carbonated MgO cement DSM pile 15 is generated after aeration for 12.0 h and the combined foundation of a carbonated DSM pile and a ventilated tubular pile is finished.

Fourth Embodiment When the natural foundation 1 is made of clay, the natural foundation has a water content of less than 10% to 20% and at a depth greater than 8 within a range up to 5 m from the ground surface m to the soil surface a water content of more than 20%. A powder addition of 15% is selected for the MgO cement and a mixture of active MgO and lime in a mixing ratio of 2: 1 is used. According to the design requirements, the diameter of the DSM pile is set to 1400 mm, the mixing depth to 16 m, the outer diameter of the ventilated tubular pile 10 to 800 mm and the length of a single ventilated tubular pile 10 to 10 m.

The construction process specifically comprises the following steps:

a. Aligning the boring bar 2 and the spiral boring head 5 of the pile machine perpendicular to an intended pile position of the natural foundation 1,

b. Switching the pile machine into a penetration state until the spiral drilling head 5 rotates to a depth of 16 m below the ground surface, the clay being cut by the spiral rotating head 5 and mixed by the mixing blade,

c. Switching the pile machine to a lifting state, spraying MgO cement powder by means of a dry spraying process while mixing and lifting at a depth of greater than 8 m to the ground surface, spraying MgO cement by means of a slurry spraying process and powder spraying process within an area at a distance of up to 5 m to the ground surface, which completes a preliminary formation of an MgO cement DSM pile body 9,

d. Lowering and raising the drill head again in accordance with steps b and c, re-mixing the MgO cement DSM pile 9 until MgO cement is evenly distributed in the MgO cement DSM pile 9,

e. Driving a first ventilable tubular pile 10 vertically into the body of the MgO cement DSMP pile 9 by means of a vibrating ramming method, lifting a second ventable tubular pile 10 when the uppermost region of the first ventilable tubular pile 10 approaches the bottom surface of the natural foundation 1, connecting the lowest area of the second ventilable tubular pile 10 firmly with the uppermost area of the first ventilable tubular pile 10, ramming of the uppermost area of the second ventilable tubular pile 10, so that the two ventilable tubular piles 10 are driven into the MgO cement DSM pile 9 in a connected state , the two ventable tubular piles 10 being connected to one another via their hollow sections,

f. Concreting the lower ventable tubular pile 10 with a concreting thickness of 4 m, driving a stainless steel sealing hood 11 into the uppermost area of the MgO cement DSM pile 9 and the ventilating tubular pile 10, the sealing hood 11 having a diameter of 1500 mm and a side wall height of 1000 mm, and inserting an aeration tube 12 into the aeration tube 10,

G. Open the pressure control valve 13 and set the ventilation pressure to 400 kPa, so that carbon dioxide gas is diffused into the pile body of the MgO cement DSM pile 9 via the ventilated tubular pile 9, with ventilation and carbonation of the pile body of the MgO cement DSM pile body 9 A carbonated MgO cement DSM pile 15 is generated after aeration for 12.0 h and the combined foundation of a carbonated DSM pile and a ventilated tubular pile is finished.

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Fifth Embodiment If the natural foundation 1 in its upper layer with a depth of up to 2 m from sandy soil, in its middle layer with a depth of 2 to 10 m from powdery soil and in the area with a depth of more than 10 m consists of clay, the natural foundation has a water content of less than 10% within a range of up to 2 m from the ground surface, and a water content of 10 within a middle range at a distance of 2 to 10 m from the ground surface % to 20% and at a depth of more than 10 m to the soil surface a water content of more than 20%. A powder addition amount of 15% is selected for the MgO cement and a mixture of active MgO, lime and cement is used in a mixing ratio of 1: 1: 1. According to the design requirement, the diameter of the DSM pile is set to 1200 mm, the mixing depth to 20 m, the outer diameter of the ventilated tubular pile 10 to 600 mm and the length of a single ventilated tubular pile 10 to 10 m.

a. Aligning the boring bar 2 and the spiral boring head 5 of the pile machine perpendicular to an intended pile position of the natural foundation 1,

b. Switching the pile machine into a penetration state until the spiral drilling head 5 penetrates rotating to a depth of 20 m below the ground surface, the natural foundation being cut by the spiral rotating head 5 and mixed by the mixing blade,

c. Switching the pile machine into a lifting state, spraying MgO cement powder by means of a dry spraying process while simultaneously mixing and lifting at a depth of greater than 10 m to the ground surface, spraying MgO cement using a slurry spraying process and powder spraying process within an area at a distance of up to 2 m to the ground surface, which completes a preliminary formation of an MgO cement DSM pile body 9,

d. Lowering and raising the drill head again according to steps b and c, re-mixing the MgO cement DSM pile 9 until MgO cement is evenly distributed in the MgO cement DSM pile 9,

e. Driving a first ventilable tubular pile 10 vertically into the body of the MgO cement DSMP pile 9 by means of a vibrating ramming method, lifting a second ventable tubular pile 10 when the uppermost region of the first ventilable tubular pile 10 approaches the bottom surface of the natural foundation 1, connecting the lowest area of the second ventilable tubular pile 10 firmly with the uppermost area of the first ventilable tubular pile 10, ramming of the uppermost area of the second ventilable tubular pile 10, so that the two ventilable tubular piles 10 are driven into the MgO cement DSM pile 9 in a connected state , the two ventable tubular piles 10 being connected to one another via their hollow sections,

f. Ramming a stainless steel sealing hood 11 into the uppermost area of the MgO cement DSM pile 9 and the ventilable tubular pile 10, the sealing hood 11 having a diameter of 1500 mm and a side wall height of 1000 mm, and inserting a ventilation tube 12 into the ventilable one Tube pile 10,

G. Open the pressure control valve 13 and set the ventilation pressure to 400 kPa, so that carbon dioxide gas is diffused into the pile body of the MgO cement DSM pile 9 via the ventilable tubular pile 9, ventilation and carbonization of the pile body of the MgO cement DSM pile body 9 a carbonated MgO cement DSM pile 15 is generated after ventilation for 8.0 h and the combined foundation of a carbonated DSM pile and a ventilated tubular pile is finished.

So far, basic principles, main features and advantages of the present invention have been illustrated and explained. It will be understood by those skilled in the art that the present invention is by no means restricted to the above examples, and the above examples and description are merely illustrative of the principles of the invention, with various changes and without departing from the basic ideas and scope of the present invention Improvements are possible that also fall within the claimed scope of the invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

claims 1. Combined foundation consisting of a carbonated DSM pile and a ventilated tubular pile, characterized in that the combined foundation consisting of a carbonated DSM pile and a ventilated tubular pile made of a carbonated MgO cement DSM pile (15) and a ventilated tubular pile ( 10), the ventilable tubular pile (10) being integrated within the carbonated MgO cement DSM pile (15). CH 713 870 B1 2. Combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 1, characterized in that the MgO cement in the carbonated MgO cement DSM pile (15) is a mixture of active MgO and quicklime, a mixture of active MgO and cement or a mixture of active MgO, quicklime and cement. 3. Combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 1, characterized in that the ventilated tubular pile (10) is a prefabricated reinforced concrete pile. 4. Construction method for the combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 1, characterized in that it comprises the following steps: a. Flattening the construction area, attaching a mixing pile machine, aligning the boring bar (2) and the spiral boring head (5) of the pile machine perpendicular to an intended pile position of the natural foundation (1), b. Switching the pile machine into a penetration state until the twist drill head (5) rotates to a predetermined depth of the natural foundation (1), the bottom of the natural foundation (1) being cut by the spiral turret (5) and broken and mixed by the mixing blade becomes, c. Switching the pile machine into a lifting state, injection of MgO cement with simultaneous mixing and lifting, which completes a preliminary formation of an MgO cement DSM pile body (9), d. Lowering and raising the drill head again according to steps b and c, re-mixing the MgO cement DSM pile (9) until MgO cement is evenly dispersed in the MgO cement DSM pile (9), e. Driving a ventilated tubular pile (10) vertically into the MgO cement DSM pile (9) before the cement floor hardens, f. Driving a sealing hood (11) into the uppermost area of the MgO cement DSM pile (9) and the ventilable tubular pile (10), inserting a ventilation pipe (12) over the sealing hood (11) into the ventilable tubular pile (10), whereby the vent pipe (12) is connected at the end protruding from the tubular pile (10) to a carbon dioxide storage container (14), a pressure control valve (13) being provided on the vent pipe (12), G. Open the pressure regulating valve (13) and adjust the ventilation pressure so that carbon dioxide gas is diffused into the pile body of the MgO cement DSM pile (9) via the ventilated tubular pile (10), whereby the pile body of the MgO cement DSM is aerated and carbonated -Pahls (9) generates a carbonated MgO cement DSM pile (15) and the combined foundation of a carbonated DSM pile and a ventilated tubular pile is finished. 5. Construction method for a combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 4, characterized in that the boring bar (2) of the pile machine is hollow in its upper region and solid in its lower region, with the lowest In the area of the boring bar (2) of the pile machine, a spiral drilling head (5) is provided, on the upper area of which a mixing blade is attached, which comprises an upper mixing blade (3) and a lower mixing blade (4), between which powder spray holes (7) and slurry spray holes ( 8) are provided, which are arranged offset from one another, a mud spray pipe (6) which is tightly connected to the mud spray holes (8) also being fastened within the boring bar (2) of the pile machine. 6. Construction method for a combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 4, characterized in that the MgO cement is a powder or sludge, the powder consisting of the powder spray holes (7) and the sludge be sprayed out of the mud spraying holes (8), the spraying out of MgO cement in the form of powder or mud being determined as a function of the water content of the natural foundation (1), the MgO cement having a water content of less than 10% in In the form of sludge, with a water content of more than 20% in the form of powder and with a water content between 10% and 20%, optionally simultaneously in the form of powder and sludge. 7. Construction method for a combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 4, characterized in that the MgO cement DSM pile (9) has a diameter of 500 to 2000 mm and the ventilable tubular pile (10) has an outer diameter of 300 to 1000 mm. 8. Construction method for a combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 4, characterized in that the ventilable tubular pile (10) is pressed hydraulically or by ramming into the pile body of the MgO cement DSM pile (9) and the length of the ventilable tubular pile (10) is not less than the pile body length of the MgO cement DSM pile (9), with a length of the ventilable tubular pile (10) being greater than the pile body length of the MgO cement DSM -Pile (9), MgO-cement-stabilized soil or concrete is filled into the ventilated tubular pile (10) until it is flush with the underside of the MgO-cement DSM pile (9). 9. Construction method for a combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 4, characterized in that the sealing hood (11) consists of hard plastic or stainless steel and has an inner diameter which is equal to or greater than the outer diameter of the MgO Cement DSM pile body (9), the depth of the side wall of the sealing hood (11) being between 100 and 1000 mm. CH 713 870 B1 10. Construction method for a combined foundation of a carbonated DSM pile and a ventilated tubular pile according to claim 4, characterized in that in step g the aeration pressure is not less than 200 kPa and determines the aeration and carbonation time depending on the property of the soil The aeration and carbonation time is between 3.0 and 6.0 hours for sandy soils, between 6.0 and 12.0 hours for powdered soils and between 8.0 and 12.0 hours for clay soils.