Background technology
For the construction of structures of building at soft foundation, if do not consider or take effective measures of foundation treatment in design or construction stage, build up the large-area surface settlement of rear easy appearance, if foundation soil is weak uneven, there will be excessive relative settlement, in construction of structures, produce crack, Damage Structure safety.
At present the method for the consolidation process of built construction thing is had to many kinds, but conventional having is following several:
Grouting and reinforcing be one for soft foundation, ground cave hole defect, foundation settlement, corrects the foundation consolidating technology of building and building tilt.There is some defect and cause uniform settlement under ground in ground, the safety of structure of superstructure has been formed to grave danger.In order to prevent that ground from continuing differential settlement, can reinforce by the slip casting of professed machine equipment in natural ground.The essence of grouting and reinforcing ground is by certain pressure, curable chemical grout or cement grout to be injected to crack or the hole of foundation soil, to improve the physical and mechanical property of ground.
Cement injection method can be divided into Pressure Revolving Blast-Grout and the large class of static pressure injection method two routinely, and these two kinds of grouting methods can be applied in Base Consolidation Engineering.In soft layer, carry out cement injection, because pressure slurries have compacted and packing action to surrounding soil in tired, extension and diffusion process, thereby change the physico-mechanical properties of foundation soil and the reaction mechanism of bearing load, improved bearing capacity of foundation soil and reduced sedimentation and deformation, having reached the object of strengthening soft foundation and underpin.Working pressure slip casting is carried out soft soil to building foundation and is processed, because cement grout setting time is longer, after clay fracturing, slit image ground is diffusion rapidly around, slurries constantly toward external diffusion, cause a large amount of wastes of slurries from gap, even surrounding enviroment are impacted; In addition,, because the viscosity of cement grout is lower, setting time is longer, the upper lifting force that slip casting produces is limited, can only carry out uncontrollable lifting and correction, under many circumstances to there is the building of differential settlement, cannot carry out lifting accurately, not reach desirable treatment effect.In addition, the waste of a large amount of cement grouts that processing procedure causes, affects environment.
Polyurethane slip casting is a kind of novel process that carries out ground base enforcement and construction of structures correction, and this technique has successfully applied to the numerous constructions of structures of the developed countries such as America and Europe and reinforced and rectify a deviation in engineering.Polyurethane slip casting method is in aperture by having been become in the ground injection polyurethane foam reaction raw materials ground that enters to need reinforcement or needs the construction of structures foundation bottom of lifting, by polyurethane foam, react the huge bulbs of pressure that produce and cementation soil mass consolidation is carried out to filling, infiltration, compacted, displacement and reinforcement effect, and to there is the construction of structures of differential settlement, rectify a deviation simultaneously.Because polyurethane reaction speed is solidified comparatively fast, and slurry viscosity is higher, and the lifting power that makes progress of generation is huge, and can by real-time grouting amount size, carry out the control of lifting amount, accomplishes the accurate control to construction of structures correction.Although polyurethane grouting method is compared with traditional cement injection method, polyurethane slip casting has numerous advantages from reinforcing lifting effect, still has some shortcomings:
1. the viscosity of polyurethane reaction raw material is high, and liquid reinforced radius is limited, easily causes the inhomogeneities of filling, and slip casting point is comparatively intensive to be occurred between slip casting point reinforcing clear area in evenly, and foundation soil space is larger;
2. according to engineering experience in the past, near slip casting point because polyurethane is comparatively intensive, the polyurethane density producing is larger, strength and stiffness are also larger, produce larger difference in height with the soil body around, under the effect of upper load, cause near the construction underpin of slip casting point to occur secondary cracking;
3. polyurethane grouting cost is high.Adopt cement injection method, every side's cement paste cost is about 100-300 unit, and adopts the every side's cost of polyurethane foam (reaction finishes rear) to be about 1500-3000 unit.After correcting offset of base lifting, still need a large amount of high polymers to carry out the filling in basic space after lifting, even if consider the lower integrated cost of high polymer grouting, high polymer grouting method still exceeds several times compared with cement injection in the reinforcement and rectification of construction underpin.
The specific embodiment
Below in conjunction with accompanying drawing, by embodiment, feature of the present utility model and other correlated characteristic are described in further detail, so that technician's of the same trade understanding:
As Fig. 1-8, in figure, mark 1-9 is respectively: basis 1, polyurethane inlet well 2, polyurethane Grouting Pipe group 3, polyurethane mud jacking equipment 4, polyurethane foam 5, cement injection boring 6, cement injection pipe group 7, cement mud jacking equipment 8, cement stabilization body 9.
Embodiment 1: differential settlement occurs on construction of structures basis, causes cracking, and structure function is imperfect or cause potential safety hazard, need to take certain engineering measure to reinforce or lifting basis.Therefore the present embodiment specifically provides a kind of associating grouting device for building foundation being reinforced and rectifying a deviation, this associating grouting device has the function of cement injection and polyurethane slip casting concurrently, reduced to greatest extent deficiency when two class grouting devices are used separately, this associating grouting device consolidation effect is even, can precisely rectify a deviation to construction of structures basis, construction simple and fast is few by slurry amount, duration is short, is a kind of economically viable grouting device.
As shown in Figure 1, associating grouting device in the present embodiment comprises polyurethane mud jacking equipment 4, polyurethane Grouting Pipe group 3, cement mud jacking equipment 8 and cement injection pipe group 7, polyurethane Grouting Pipe group 3 is arranged in the polyurethane inlet well 2 of building foundation 1 and is connected with polyurethane mud jacking equipment 4, cement injection pipe group 7 is arranged in the cement injection boring 6 of building foundation 1 and is connected with cement mud jacking equipment 8, for convenient mobile and transportation, cement mud jacking equipment 8 and polyurethane mud jacking equipment 4 can integrated installation on same car body, also can be arranged on as shown in Figure 1 on car body separately, wherein, cement injection pipe group 7 is spaced apart between polyurethane Grouting Pipe group 3, spacing distance is between 0.5m~10m, three Grouting Pipe of polyurethane Grouting Pipe group 3 different depth in going deep into polyurethane boring 2 form, three Grouting Pipe of cement injection pipe group 7 different depth in going deep into cement injection boring 6 form, no matter be polyurethane Grouting Pipe or cement injection pipe, by its grout outlet being arranged to the different depth place of boring, in the time of can preventing polyurethane reaction raw slurry or cement grout slip casting, produce and stop up, guarantee squeezing quality.
As shown in Fig. 1-8, adopt and in the present embodiment, to combine that grouting device is reinforced building foundation and the construction sequence of rectifying a deviation is as follows:
[step 1] arranges polyurethane inlet well 2
As shown in Figure 2,3, there is sedimentation in building foundation 1, in building foundation 1, settling amount maximum is arranged polyurethane inlet well 2, the diameter of polyurethane inlet well 2 is 14cm-30cm, the degree of depth of polyurethane inlet well 2 can be between the 1 following 0.1m-10m of basis, and the slip casting degree of depth is specifically determined by place geological condition and upper load situation;
[step 2] transfers polyurethane Grouting Pipe group 3
As shown in Figure 3, after pore-forming, verification holes position, hole depth and verticality, after all meeting the demands, transfer polyurethane Grouting Pipe group 3 by hole depth;
If the degree of depth of polyurethane inlet well 2 be basis 1 following 0.1m~1m between time, polyurethane Grouting Pipe group 3 consists of single polyurethane Grouting Pipe;
If the degree of depth of polyurethane inlet well 2 be basis 1 following 1m~10m between time, polyurethane Grouting Pipe group 3 at least consists of two polyurethane Grouting Pipe, in the present embodiment, three polyurethane Grouting Pipe, consist of, the vertical interval between each polyurethane Grouting Pipe grout outlet is 1m;
[step 3] carries out the slip casting of polyurethane reaction raw slurry
As shown in Fig. 3,4,5, adopt polyurethane mud jacking equipment 4 to enter in the basis 1 that maybe needs correction in the ground needing reinforcement by the polyurethane Grouting Pipe group 3 injection polyurethane reaction raw slurries of arranging in ground; First to being embedded in the polyurethane Grouting Pipe in deep in polyurethane Grouting Pipe group 3, carry out slip casting, polyurethane reaction raw slurry generation chemical reaction forms polyurethane foam 5, after slip casting reaches requirement, be embedded in the slip casting of the polyurethane Grouting Pipe of superficial part, until carry out basis 1 reinforcing and lifting by being embedded in the polyurethane Grouting Pipe of basic 1 bottom surface, wait reach setting basis 1 rising height or reinforce target after stop slip casting; The rising height of described surface of base is determined by the real-time monitored Instrument observation arranging;
There is chemical reaction from bottom to top and expand in the former slip of polyurethane reaction, constantly expansion curing forms vertical reinforcement, and lifting is carried out in construction of structures basis 1, and the former slip of this polyurethane reaction is injected mixing according to weight ratio 1:0.1~1:10 by Double-liquid mud-injection pump by A component and B component, wherein
A component comprises one or more cyanates a, and cyanate can represent by general formula R (NCO) n, wherein R represent aliphatic alkyl containing 2-18 carbon atom, containing the aryl of 6-15 carbon atom, contain 8-15 carbon atom aryl aliphatic hydrocarbyl, n=2-4;
B component comprises polyalcohol b, chain extender c, blowing agent d and catalyzer e, concrete, polyalcohol b is the mixture of a kind of polyalcohol or multiple polyalcohol, the mean molecule quantity of polyalcohol is 100-10000, degree of functionality is 2-10, the mixture that described chain extender c is one or more chain extenders, be molecular weight be less than 800 containing reactive hydrogen atom compound; Blowing agent d selects water, halogenated hydrocarbons, hydrocarbon compound, gas etc., consumption is the 0.3%-15.0% of b and c weight, catalyzer e is amines catalyst, organo-metallic catalyst or their mixture, and consumption is the weight 0.001%-10.0% of b and c, under-10 ° of C-100 ° of C;
Above-mentioned A component and B component are mixed generation chemical reaction, generate polyurethane foam, are the resins that contains repetition-HNCO-O-group on main chain;
[step 4] arranges cement injection boring 6, and arranges cement injection pipe group 7
As shown in Figure 6, until step 3, complete after at least 15 minutes, within the scope of polyurethane Grouting Pipe 30 both sides 0.5m-10m, arrange cement injection boring 6, drill hole density is determined according to grouting and reinforcing lifting scope, press 3-30 square metre and arrange a boring, bore diameter is 20mm-100mm, the degree of depth is basic 1 below 0.1m-10m, after pore-forming, insert cement injection pipe group 7, this cement injection pipe group 7 consists of three cement injection pipes in the present embodiment, and the grout outlet vertical interval of each cement injection pipe is not more than 2.0m;
[step 5] carries out cement injection filling
As Fig. 5, shown in 6, in the hole that adopts cement mud jacking equipment 8 to enter by the cement injection pipe group 7 cement injection grouting serous fluids of arranging in ground in the basis 1 that maybe needs correction in the ground needing reinforcement and produce in polyurethane slip-casting lifting process before, the concrete steps of perfusion are: first to being embedded in the cement injection pipe in deep in cement injection pipe group 7, carry out slip casting, after grouting pressure reaches designing requirement, to being embedded in the cement injection pipe of superficial part, carry out slip casting, until by being embedded in, the cement injection pipe of basic 1 bottom surface carries out 1 time, basis hole and fill in space, after reaching designing requirement, grouting pressure stops slip casting, behind hole in the curing soft foundation of cement paste and filling ground and space, form cement stabilization body 9,
[step 6] slip casting curing time
Until above-mentioned steps, complete after 14 days-28 days, the reinforcing on construction of structures basis 1 and correction finish, and can again come into operation, and construction finishes.
In the present embodiment, by employing, combine polyurethane Grouting Pipe group in grouting device construction of structures is carried out to lifting, the space producing after simultaneously adopting cement injection pipe group in associating grouting device to the hole, space and the polyurethane slip casting jacking of foundation that are reinforced soil body Central Plains and pre-exist is filled and is reinforced, and its specific works principle is as follows:
As shown in Fig. 1-8, on construction of structures basis, 1 sedimentation larger part is sent into polyurethane Grouting Pipe group 3 in the hole of projected depth, by polyurethane special slip casting equipment 4 injection urethane raw reacting slurry A, B component, enter ground, there is chemical reaction fast in polyurethane reaction raw material A, B component, expanding volume is doubly former reaction raw materials slurries liquid volume of 5-30, produce the bulbs of pressure up to 400kPa simultaneously, high compression swelling produces powerful compacted effect and metathesis to surrounding soil, even under certain pressure, clay fracturing is reinforced.Slip casting is to lower and go up, and urethane raw constantly reacts and forms vertical reinforcement, near basic 1 bottom surface, is locating, constantly carry out polyurethane slip casting, the huge expansion force that reaction produces, by acting on the existing construction of structures basis 1 that differential settlement occurs, continues slip casting, and lifting, correction are carried out in basis 1.Now, because the viscosity of polyurethane reaction raw slurry is higher very fast with the reaction time, liquid reinforced radius is limited, in construction underpin 1 lifting process, except near slip casting place, construction of structures basis 1 will form larger space around, add space and hole in former weak foundation soil, cause the inhomogeneities of filling and poor consolidation effect, according to engineering experience in the past, construction of structures basis 1(after the slip casting of employing polyurethane is as speedway), near slip casting point, easily producing stress concentrates, through after a period of time, poor rigidity due to ground, cause construction underpin 1 to occur cracking.Consider this point, the present embodiment is innovated cement injection and polyurethane slip casting is organically combined by associating grouting device, after polyurethane slip casting, adopts cement injection to carry out filling to construction of structures basis, foundation soil is reinforced and filled, and cement paste will form good regulation effect after solidifying.
The advantage of the present embodiment is as follows:
(1) this associating grouting device is simple in structure, simple operation, low cost of manufacture;
(2) this associating grouting device can carry out the lifting of fast accurate to construction of structures, and by adopting polyurethane Grouting Pipe group to reinforce lifting, the polyurethane reaction time is rapid, and rising height is controlled;
(3) this associating grouting device has good reinforcing lifting effect, by adopting polyurethane Grouting Pipe group, construction of structures basis is reinforced to lifting accurately, and inject the good cement grout of mobility by cement injection pipe group, the basic space of construction of structures, soil mass consolidation hole are carried out to filling, utilize the solidification effect of cement grout to reinforce weak foundation soil, reach all even comprehensive consolidation effects;
(4) economical rationality, because polyurethane reaction raw slurry unit price is higher, this associating grouting device, by adopting cement injection pipe group to carry out filling reinforcing to hole and space, greatly reduces the use amount of polyurethane reaction raw slurry, has reduced construction costs and can reach 1/2-1/3.
Embodiment 2: in the present embodiment; in polyurethane Grouting Pipe group, be arranged with flexible pile bag, one end outer wall of the sack of this flexible pile bag and polyurethane Grouting Pipe group is tightly connected, due to the effect of peripheral flexible pile bag; urethane raw reacting slurry can arbitrarily not spread, and has protected underground environment.All the other structures of combining grouting device in the present embodiment are all identical with the associating grouting device structure in embodiment 1, therefore repeat no more.