CN106013048A - Super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading - Google Patents

Abstract

The invention relates to a super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading. The super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading is characterized by comprising the following steps that step one, an integrated well point plastic drain vacuum system is arranged, specifically, 1.1, integrated well point plastic drain pipes are subjected to insertion construction to form an integrated well point plastic drain pipe grid, and 1.2, the integrated well point plastic drain vacuum system is formed by connecting the integrated well point plastic drain pipe grid with a header pipe and a vacuum pump; step two, vacuum preloading is conducted; and step three, vacuum dewatering preloading is conducted. The super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading has the advantages of being easy to operate, low in cost and good in construction effect.

Description

Ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method

Technical field

The present invention relates to a kind of underwater processing method, particularly relate to a kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method.

Background technology

One, conventional ultra-soft foundation, plant equipment cannot be walked thereon and construct, often be used and manually plug shallow-layer plastic draining board, manually lays sand bedding course and geotextiles diaphragm seal carries out vacuum pre-press reinforcing, but have the disadvantage in that

1, large area diaphragm seal difficulty of construction is big, and land vacuum preloading needs a large amount of artificial plastic film mulch mechanization degree low；

2, the low easy damaged gas leakage of pvc diaphragm seal intensity, one layer of geotextiles cost height of two layers of diaphragm seal, search air leakage point difficult；

3, substantial amounts of pvc diaphragm seal is not environmentally；

4, under film, earth's surface is maximum up to negative pressure 80kPa, and negative pressure is fast toward soil layer deep slippages, typically transmits about every meter of loss negative pressure 10kPa toward deep, and about 8 to 10 meters of earth's surface following soft soil vacuum preloading weak effect, effective reinforcement depth is shallow；

5, loading surface is at original place table or backfill soil table, even if top layer diaphragm seal is air tight, the stabilization zone surrounding shallow-layer soil body leaks gas slowly and still cannot ignore, and in the case of especially about 90 days long time loading, drops to a certain degree stabilization zone surrounding shallow soil body drain gas degree in level of ground water and more causes anxiety.

Two, follow-on vacuum pre-press reinforcing has the disadvantage in that

1, going sand bedding course to change hand-type joint direct-connected plastic strip plate mode into, change indirect transfer negative pressure and transmit negative pressure pattern for direct, but it remains a need for diaphragm seal, peak suction loading surface is still on earth's surface；

2, serous fluid of dredger fill forms sealant or the direct-connected plastic strip of vacuum manifold and buries about 1.5 meters or 3 meters, vacuum chimney filter underground left and right sides plastic uptake row's replacement seal film, 10 days vacuum preloading initial stages right-left seal is preferable, but along with serous fluid of dredger fill dehydration consolidation cracking, level of ground water rapid decrease, sealing effectiveness is had a greatly reduced quality；

3, reclaiming fields from the sea ultra-soft soil cannot mechanical execution, first do artificial plate shallow-layer plastic strip vacuum preloading, treat that its foundation strength is suitable for mechanical execution, do deep vacuum precompressed again, ultra-soft soil vacuum preloading of reclaiming fields from the sea is the most consistent with conventional vacuum precompressed principle technique, artificial and the most mechanical simple difference, process is more complicated, and cost is high, efficiency is low；

90 days underground water level decreasing of vacuum preloading are typically only 1 ~ 3 meter, actual application typically processes deep soft soil foundation, shallow-layer poor effect, reinforces groundwork bearing capacity in theory and is generally about 80kPa, and reality is applied, and shallow top layer foundation bearing capacity is the most too low even only has 30 ~ 50kPa.

Summary of the invention

It is an object of the invention to overcome above-mentioned deficiency, it is provided that a kind of ultra-soft foundation vacuum preloading seepage consolidation simple to operate, with low cost, that construction effect is good combines precipitating, pre-pressing concretion method.

The object of the present invention is achieved like this:

Compared with prior art, the invention has the beneficial effects as follows:

1, sealing system improvement one:

By using the shallow-layer soil body at the well-point pipe of integral type well point plastic strip vacuum system as first sealant；Good sealing effect, simple and reliable, saving material of constructing；

2, sealing system improvement two:

Region surface water-stop to be reinforced in cofferdam, forms second sealant；

3, Vacuum Loading System improvement one:

Conventional vacuum precompressed, 80KPa negative pressure of vacuum loads and is each provided at earth's surface, after improvement, 80KPa negative pressure maximum is positioned at the earth's surface following shallow-layer soil body and deep soil junction, improve certain depth (first sealant i.e. the degree of depth of the shallow-layer soil body) by improvement vacuum preloading effective reinforcement depth theoretically, decrease simultaneously and treat the reinforcing area the best negative effect brought of surrounding shallow-layer sealing effectiveness；

4, Vacuum Loading System improvement two:

nullConventional vacuum precompressed employings etc. carry compression system，Except early stage is in order to check leaking source and slow down plastic strip earth pillar formation turn on pump rate 60% ~ 80%，Later stage maintains the negative pressure saving energy also to maintain turn on pump rate not less than 80%，Other situation is the most unchanged，After improvement，Use hierarchical loading，Until settling stabilization under this grade of negative pressure load，Improve one-level load level the most again and continue pressurization，Until it is stable，Circulate successively，Step up zone negative pressure to be reinforced to maximum，It is similar to static load test hierarchical loading，Also the work progress of construction multistage loadings is simulated，Consolidation pattern is loaded for varying stress path，Facts have proved，Although conventional vacuum precompressed achieves earth's surface negative pressure 80kPa load level，But the earth's surface following different depth soil body reaches far away more than 80kPa full load condition，This is bigger mistaken ideas，After improvement，The different depth soil body can be realized by unlimited increase vacuum pump quantity in theory by hierarchical loading and all reach the fully loaded negative pressure reinforcing state of more than theoretical limit 80kPa.nullThis improvement is greatly improved vacuum preloading limit consolidation effect，And conventional vacuum precompressed is difficult to infinitely improve vacuum pump quantity and realizes hierarchical loading，Its reason is: one，The more difficult random increase vacuum pump quantity of sealing system membrane system complex，Once can only lay by predetermined number，Vacuum pump quantity cannot be adjusted according to Monitoring Data and realize dynamic load，They are two years old、Along with vacuum pump quantity is continuously increased，Level of ground water declines too fast，The level of ground water above surrounding soil body forms bigger leaking source，The helpless less effective that seem in face of the huge leaking source of semi-infinite body ground such as conventional employing clay envelope wall soil cement envelope wall，The slow gas leakage that the earth's surface sealing system that process materials limits at present shows under ever-increasing vacuum level，Cause the circulation forming a limiting equilibrium，Therefore conventional vacuum is pressed with the vacuum pump quantity of a balance in advance，Also every the vacuum pump processing area 800 ~ 1500 squares often said in specification.This is also vacuum preloading 90 days, the theoretical source of 800 ~ 1500 squares of fixed pattern conclusions of every vacuum pump processing area, after improvement, the groundwater recharge of suction to ground top layer or recharges to ground surrounding, form reinforcing area body of groundwater seepage flow self-circulation system, preferably achieve the vacuum preloading of hierarchical loading；

5, Vacuum Loading System improvement three:

nullConventional vacuum covers the double effects that aqueous mode has sealing and water-water reactor to carry in advance，But cut off due to the existence of diaphragm seal and covered water to the supply of soil mass consolidation seepage flow，Subsoil water self-circulation system can not be formed，Effect is had a greatly reduced quality，After improvement，Groundwater recharge to the foundation surface nature seepage flow of suction is replenished to ground and forms circulation，Not lowering of watertable vacuum seepage preloading method construction，Cover Water Spreading system and avoided the occurrence of that first 20 days water yields of conventional vacuum precompressed are the most satisfactory for result to be reduced along with the jet pump efficiency that gradually reduces of water yield、Shallow-layer sealing system is less effective in the case of level of ground water reduces，The problems such as pre-compressed effect gradually reduces，This improves topmost theory and is the discovery that: 1、Water is conducive to consolidation than the soil body interstitial air after reducing water level as negative pressure carrier as negative pressure carrier，Can be understood as seepage consolidation or the flow of water poor (negative pressure causes) seepage consolidation，And water is little as the transmission negative pressure loss of negative pressure carrier，Thus it is extended to the simple realization of underwater vacuum precompression.null2、Effect in the precipitating, pre-pressing effect the most conventional ground theory imagination is obvious，The precipitating, pre-pressing theory actual measurement performance that after precipitation, the water buoyancy deadweight of level of ground water above soil body deduction increases is general，Its principle is still needed and is studied further，But more at least it may be mentioned that，After vacuum preloading, soil body saturation has no that reducing some improves on the contrary，Even if soil body deadweight increases after assuming precipitation，But the above soil strength of level of ground water has obtained bigger raising after precipitation the most simultaneously，The above soil deformation of level of ground water counteracts the increase of the deadweight pre-compressed effect to the bottom soil body due to raising and the crust layer soil arching effect relatively of intensity，Actual measurement level of ground water reduction is the most too fast (is reduced to lower about 8 meters of earth's surface，Usually do not include the level of ground water of negative pressure about 7 meters decline the overload that causes also at 70kPa to less than 8 meters soil body surcharge preloadings，Consolidation settlement should significantly increase，But survey unsatisfactory，And quickly stable)，On the premise of excess pore water pressure is almost unchanged, soil solidifying is relatively stable too early on the contrary，So inferring，Lowering of watertable causes the deadweight increase of the settlement of foundation main cause non-aqueous buoyancy disappearance soil body to cause，But flow of water difference causes the settlement of foundation that seepage force causes，At least seepage force is the leading factor that sedimentation occurs，So lowering of watertable need not be used to form precipitating, pre-pressing strengthen vacuum preloading effect.3, conventional vacuum precompressed level of ground water reduces inconspicuous general 2 ~ 3 meters, the soft soil foundation vacuum preloading of 90% below 2 ~ 3 meters of levels of ground water the most under water or is carried out in water, illustrate not lowering of watertable vacuum preloading be can realize and also negative pressure transmission effect is more preferable；

Being improved to based on above-mentioned analysis: lowering of watertable does not covers the construction of Water Spreading vacuum method, it is achieved water covering prepressing, cover water seepage flow, cover water-stop, vacuum seepage consolidates, and measured result is preferable

6, vaccum pump unit improves

Conventional vacuum precompressed uses open type to carry out vacuum preloading from the jet pump that overflows, it is improved to the sealed vacuum jet pump that conventional light well point is used, it is easy to maintaining, extension device service life, simultaneously facilitate the perfect linking realizing vacuum preloading and Dewatering dynamic compaction construction, use same equipment same house steward's same integral type well point plastic strip vacuum system to complete " vacuum preloading, precipitating, pre-pressing " foundation stabilization task.

7, the improvement of house steward:

Conventional vacuum precompressed house steward is equal diameter pvc pipe or galvanized pipe etc., improving transverse tube uses the transverse tube segmentation of the necking section with self-control venturi jet effect to improve vacuumizing effect, additionally uses manifold linkage section to substitute tradition threeway and improves tubing utilization rate and efficiency of assembling；

8, draining board improves:

Conventional Degradable plastic water drainage plate is central layer degraded, actual degradation effect is the best, improves draining board and uses filter membrane degradable biological material, does not stay drainage channel to reduce settlement after construction after environmental protection and work, central layer, without degraded, reduces cost central layer simultaneously as reinforcement material reinforcing soft soil；

9, the residual settlement that the plastic draining board of conventional vacuum precompressed residual is certain after often causing work, especially construction period fails the soft soil foundation fully consolidated, slow consolidation settlement under work after load long term, form disease, after improvement, the superstructure of integral type well point plastic strip pipe (connects box, well-point pipe and connecting tube) can pull out, after vacuum preloading completes, pipe extractor is used to pull out the superstructure of integral type well point plastic strip pipe, the superstructure of integral type well point plastic strip pipe can reuse, noresidue drainage channel in shallow soil body under earth's surface simultaneously, draining board under the shallow-layer soil body does not stay drainage channel after realizing overall work, reduce residual settlement after work；

10, conventional vacuum precompressed suction subsoil water, easily causes the bigger sedimentation of surrounding, constructs by being improved to cover Water Spreading not lowering of watertable vacuum seepage preloading method, it is possible to reduce the impact on surrounding；

11, Water Spreading not lowering of watertable is covered, vacuum dewatering preloading house steward and arm water yield are big, subsoil water goes round and begins again circulation seepage flow, guarantee that vacuum pump and house steward, manifold system work under the full negative pressure state of full water, formation negative pressure is high, actual measurement uses less vacuum pump that large-area treatment region i.e. can be allowed to reach the full table status of negative pressure 90 ~ 100kPa, and vacuum pump does not haves hydropenia yet and burns pump phenomenon；

null12、Conventional precipitation well point mechanical hole building is not often taken out water and is formed dried-up well，General recommendation uses artificial water jetting pore-forming，General 200 ~ the 300mm in aperture，General about 1 meter of filter，Pore-forming is the best often cannot water outlet，Cloth dot spacing is rammed walking be also impossible to the closeest owing to being looked after，The limited water lift of light well point vacuum-dewatering principle is height-limited，The light well point that document finding is the deepest at present is the most just at about 7 meters，Consider precipitation funnel，Therefore level of ground water reduces limit depth about 4 ~ 5 meters only，It is required to backfill medium coarse sand and guarantees water recharging，Water yield is less，Cause vacuum jet pump negative pressure to reduce and comparatively fast affect vacuum-dewatering effect，But this causes well point gas leakage negative pressure the highest and leaves sand drain after work and continues the unfavorable factors such as drainage subsidence simultaneously，Therefore present follow-on precipitation popular employing deep-well precipitation or tube well dewatering，But layouting in view of two kinds of dewatering modes can not be the closeest，Precipitation effect can only be played，It is difficult to play vacuum preloading effect，Integral type well point plastic strip vacuum system，The filter degree of depth can be deeper than vacuum-dewatering well point，Take into account gravity precipitation and vacuum-dewatering，Low price is suitable for large area and lays，Not only improve precipitation，Be conducive to again vacuum preloading，Realize mechanized construction pore-forming efficiency high，Owing to filter uses the overlength plastic draining board that water-flowing amount is higher，Dried-up well rate is almost nil，Either precipitation depth is also or precipitation efficiency can substitute above-mentioned various precipitation with perfection completely and gently ram mode；

13, early stage uses not lowering of watertable to cover Water Spreading vacuum seepage consolidation precompressed ground, treat vacuum preloading settlement stability, open the water (about conventional depth of water 50cm) that cofferdam earial drainage is stored, continue while quick lowering of watertable plays the vacuum preloading taking into account precipitating, pre-pressing effect, complete precipitation dewatering construction, after improvement can quickly lowering of watertable to 5 ~ 8 meters；

14, conventional vacuum precompressed dewatering effect is not good enough, conventional precipitating, pre-pressing does not has vacuum preloading effect, integral type well point plastic strip vacuum system is laid substantial amounts of draining board and is replaced shorter filter, i.e. can realize quick lowering of watertable, can also efficiently realize vacuum seepage precompressed, a kind of 2 kinds of effects of material, it is achieved the purpose of a material multipurpose efficiency energy saving；

15, this method is particularly suited for ultra-soft foundation reinforcing of reclaiming fields from the sea, its implementation is, insert integral type well point plastic strip pipe by simple artificial, it is achieved the shallow-layer vacuum preloading that preferably seals, vacuum-dewatering, rapidly and efficiently reinforce ultra-soft foundation so that the expansion of subsequent mechanical construction.

Therefore the present invention has advantage simple to operate, with low cost, that construction effect is good.

Accompanying drawing explanation

Fig. 1 is the elevational schematic view of the integral type well point plastic strip vacuum system of the present invention.

Fig. 2 is the schematic top plan view of the integral type well point plastic strip vacuum system of the present invention.

Fig. 3 is the structural representation of the integral type well point plastic strip pipe of the present invention.

Fig. 4 is the sectional view of the draining board of the present invention.

Fig. 5 is the structural representation connecting box of the present invention.

Fig. 6 is enlarged drawing at the A in Fig. 2.

Fig. 7 is the schematic diagram of the transverse tube in Fig. 6.

Fig. 8 is enlarged drawing at the B in Fig. 2.

Wherein:

Draining board 1, central layer 1.1, main gusset 1.11, secondary gusset 1.12, filter membrane 1.2, drainage channel 1.3

Connect box 2, housing 2.1, lower interface 2.2, upper interface 2.3, screw hole 2.4

Well-point pipe 3

Connecting tube 4

Transverse tube 5, transverse tube segmentation 5.1, straight length the 5.11, first Taper Pipe section the 5.12, second Taper Pipe section 5.13, manifold linkage section 5.2, linkage section main body 5.21, transverse tube segmentation interface 5.22, connecting tube interface 5.23

Longitudinal tubule (L tubule) 6, longitudinal tubule (L tubule) segmentation 6.1, three way cock 6.2, check valve 6.3

Vacuum pump 7

Deep soil 100

The shallow-layer soil body 200.

Detailed description of the invention

Seeing Fig. 1 ~ Fig. 8, a kind of ultra-soft foundation vacuum preloading seepage consolidation that the present invention relates to combines precipitating, pre-pressing concretion method, and it comprises the following steps:

Step one, integral type well point plastic strip vacuum system are arranged

1.1, plastic strip pipe in integral type well point carries out plugging construction and forms integral type well point plastic strip pipe network lattice；

Mesh spacing 1 ~ the 4m of integral type well point plastic strip pipe network lattice is adjustable；Artificial plate is used to carry out plugging of integral type well point plastic strip pipe.

Integral type well point plastic strip pipe (arm after namely improving) includes draining board 1, connects box 2, well-point pipe 3 and connecting tube 4, described draining board 1 is vertically arranged in deep soil 100, a length of about the 20m of draining board 1, described well-point pipe 3 is vertically arranged in the shallow-layer soil body 200, a length of 6 ~ the 9m of well-point pipe 3, the upper end of draining board 1 is connected with the lower end of well-point pipe 3 by connecting box 2, the upper end of well-point pipe 3 is exposed outside the shallow-layer soil body 200, the upper end of well-point pipe 3 is connected with one end of connecting tube 4, a length of 1 ~ 2m of connecting tube 4.Well-point pipe 3 and a diameter of 10 ~ 20mm of connecting tube 4.

Draining board 1 includes central layer 1.1 and the filter membrane 1.2 of central layer 1.1 periphery of inside, drainage channel 1.3 is formed between described central layer 1.1 and filter membrane 1.2, described central layer 1.1 is made for non-degradable material or difficult degradation material, and described filter membrane 1.2 is made for degradation material.

Preferred as one, central layer 1.1 is made for plastic material, and filter membrane 1.2 is made for Caulis et Folium Lini material.

Preferred as one, central layer 1.1 includes the main gusset 1.11 of a lateral arrangement and the many longitudinally spaced secondary gussets 1.12 being arranged in before and after main gusset 1.11, and main ribs plate 1.11, the space formed between secondary gusset 1.12 and filter membrane 1.2 are drainage channel 1.3.

After draining board 1 inserts ground, as time goes by, owing to filter membrane 1.2 uses degradation material to make, filter membrane 1.2 realizes fast degradation, filter membrane 1.2 degraded after in ground the most remaining central layer 1.1, soil in ground can fill former filter membrane 1.2 and the space of former drainage channel 1.3, soil is fitted tightly with central layer 1.1, therefore central layer 1.1 the most do not exist in ground space make ground continue sedimentation, but also serve the effect of reinforcement, the integraty of the most different floor heights in improve ground.

The lower end of described draining board 1 is provided with bottom discharge plate end socket, and bottom discharge plate end socket uses plastic adhesive tape paper to be wrapped to form.

Described connection box 2 includes housing 2.1, the lower end of described housing 2.1 is provided with a lower interface 2.2 coincideing with draining board 1 upper end shape, the upper end of described connection box 2 is provided with a upper interface 2.3 coincideing with well-point pipe 3 lower end shape, three screw holes 2.4 it are provided with on described housing 2.1, the rectangular in cross-section structure of described lower interface 2.2, during installation, the upper end of draining board 1 is inserted at lower interface 2.2, then in screw hole 2.4, draining board 1 and connection box 2 are connected in one by drivescrew, then dress outside plastic adhesive tape at lower interface 2.2.Described upper interface 2.3 is circular tube structure, and during installation, the lower end of well-point pipe 3 is sheathed on outside interface 2.3, then the lower end of upper interface 2.3 with well-point pipe 3 is dressed outside plastic adhesive tape.

Described connecting tube 4 is wired hose, and connecting tube 4 includes the spiral wire of flexible pipe and Lining Hose.

Described well-point pipe 3 is the plastic tubes such as PPR, and well-point pipe 3 and connecting tube 4 junction are wrapped up by diaphragm seal or steel wire winding, after using diaphragm seal parcel, produces negative-pressure dense sealer when integral type well point plastic strip pipe evacuation and is inhaled tighter and tighter.Well-point pipe 3 can also use with connecting tube 4 as wired hose so that well-point pipe 3 and connecting tube 4 form integrative-structure.

1.2, integral type well point plastic strip pipe Mesh connection house steward and vacuum pump form integral type well point plastic strip vacuum system.Described house steward includes longitudinal tubule (L tubule) 6 and the many transverse tubes 5 being connected on longitudinal tubule (L tubule) 6.

nullDescribed transverse tube 5 is formed by connecting by multiple transverse tube segmentations 5.1 and manifold linkage section 5.2，It is attached by manifold linkage section 5.2 between adjacent two transverse tube segmentations 5.1，Manifold linkage section 5.2 preferably employs eight as one and leads to linkage section，Eight lead to linkage section includes linkage section main body 5.21，The two ends, left and right of linkage section main body are respectively arranged with transverse tube segmentation interface 5.22，Linkage section main body 5.21 is forwardly and rearwardly respectively arranged with three connecting tube interfaces 5.23，The adjacent connecting tube 4 of connecting tube interface 5.23 is attached，The adjacent transverse tube segmentation 5.1 of transverse tube segmentation interface 5.22 connects，Described transverse tube segmentation 5.1 includes a necking section，Necking section is arranged near manifold linkage section 5.2，Described transverse tube segmentation 5.1 also includes straight length 5.11，Described necking section includes the first Taper Pipe section 5.12 and the second Taper Pipe section 5.13，The little head end of the first Taper Pipe section 5.12 and the little head end docking of the second Taper Pipe section 5.13，The stub end of the first Taper Pipe section 5.12 is adjacent the transverse tube segmentation interface 5.22 of manifold linkage section 5.2 and docks，The stub end of the second Taper Pipe section 5.13 docks with one end of straight length 5.11，The transverse tube segmentation interface 5.22 of the manifold linkage section 5.2 that the other end of straight length 5.11 is adjacent docks.The tapering of the first Taper Pipe section 5.12 forms venturi jet effect more than the tapering of the second Taper Pipe section 5.13, necking section.

Described longitudinal tubule (L tubule) 6 is vertically connected at one end of all transverse tubes 5, and transverse tube 5 is provided with transverse tube end socket away from one end of longitudinal tubule (L tubule) 6, and the necking section of the transverse tube segmentation 5.1 on transverse tube 5 is away from longitudinal tubule (L tubule) 6, and the straight length 5.11 of the transverse tube segmentation 5.1 on transverse tube 5 is near longitudinal tubule (L tubule) 6.A piece longitudinal tubule (L tubule) 6 connects many transverse tubes 5, described longitudinal tubule (L tubule) 6 is formed by connecting by multiple longitudinal tubule (L tubule) segmentations 6.1 and three way cock 6.2, adjacent two longitudinal tubule (L tubule) segmentations 6.1 are connected by three way cock 6.2,3rd interface of three way cock 6.2 connects the transverse tube 5 closed on, being additionally provided with check valve 6.3 in longitudinal tubule (L tubule) segmentation 6.1, the end of longitudinal tubule (L tubule) 6 is provided with longitudinal tubule (L tubule) end socket.

Step 2, vacuum preloading

Integral type well point plastic strip vacuum system starts vacuum preloading 30 ~ 90 days.Aspirate subsoil water during vacuum preloading all to recharge to the cofferdam fill treating reinforcing area；

Its intermediate pump 7 is preferably sealed vacuum jet pump, vacuum pump evacuation uses hierarchical loading evacuation: it is adjustable that the vacuum pump hierarchical loading first order takes every vacuum pump processing area 1800 ~ 2000 squares, first section of negative pressure of house steward is full table 100kPa, house steward's end is not less than 90kPa, treat that sedimentation meets sedimentation for three days on end and is not more than 3 millimeters, it is adjustable that the vacuum pump hierarchical loading second level takes every vacuum pump processing area 1300 ~ 1500 squares, treat that sedimentation meets sedimentation for three days on end and is not more than 3 millimeters, the vacuum pump hierarchical loading third level takes every vacuum pump processing area 800 ~ 1000 squares or following adjustable, by that analogy, treat that sedimentation meets sedimentation in continuous 5 days and is not more than 2 millimeters, reach vacuum preloading and process requirement；

Step 3, vacuum dewatering preloading

Excavate the water that stored in the earial drainage cofferdam fill of cofferdam in gutter, start vacuum dewatering preloading, carry out for the purpose of precipitating, pre-pressing by lowering of watertable, treat that level of ground water reaches requirement (level of ground water reaches below ground 4 ~ 8m) and maintains 10 ~ 30 day time of level of ground water, complete the precipitating, pre-pressing of some cycles until ground settlement is stable, terminate precipitating, pre-pressing.

If step 4 need to be reinforced further, precipitating, pre-pressing and the multipass that can carry out multipass on aforementioned base gently ram, and form certain thickness crust layer.

Note: integral type well point plastic strip vacuum system can adjust spacing and length according to place and soil property situation, construction period construction monitoring must synchronize to carry out, the monitoring project that have to carry out has: pore water pressure, level of ground water, ground settlement, delaminating deposition, vacuum, it is achieved information-aided construction.

Claims (10)

1. a ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method, it is characterised in that it comprises the following steps:

A kind of ultra-soft foundation vacuum preloading seepage consolidation combines precipitating, pre-pressing concretion method, and it comprises the following steps:

Step one, integral type well point plastic strip vacuum system are arranged

1.1, plastic strip pipe in integral type well point carries out plugging construction and forms integral type well point plastic strip pipe network lattice；

Integral type well point plastic strip pipe includes draining board, connects box, well-point pipe and connecting tube, described draining board is vertically arranged in deep soil, described well-point pipe is vertically arranged in shallow soil body, the upper end of draining board is connected with the lower end of well-point pipe by connecting box, it is external that shallow soil is exposed in the upper end of well-point pipe, and the upper end of well-point pipe is connected with one end of connecting tube；

1.2, integral type well point plastic strip pipe Mesh connection house steward and vacuum pump form integral type well point plastic strip vacuum system；

Step 2, vacuum preloading

Integral type well point plastic strip vacuum system starts vacuum preloading；

Step 3, vacuum dewatering preloading

Excavate the water that stored in the earial drainage cofferdam fill of cofferdam in gutter, start vacuum dewatering preloading, for the purpose of lowering of watertable, treat that level of ground water reaches requirement, complete the vacuum dewatering preloading of some cycles until ground settlement is stable, end precipitating, pre-pressing；

Step 4, as required after vacuum dewatering preloading on the basis of carry out the vacuum dewatering preloading of multipass and multipass gently rams, form certain thickness crust layer.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 1, it is characterised in that vacuum pump evacuation uses hierarchical loading evacuation.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 2, it is characterized in that vacuum pump hierarchical loading vacuum step is as follows: the vacuum pump hierarchical loading first order takes every vacuum pump processing area 1800 ~ 2000 squares, first section of negative pressure of house steward is full table 100kPa, house steward's end is not less than 90kPa, treat that sedimentation meets sedimentation for three days on end and is not more than 3 millimeters, the vacuum pump hierarchical loading second level takes every vacuum pump processing area 1300 ~ 1500 squares, treat that sedimentation meets sedimentation for three days on end and is not more than 3 millimeters, the vacuum pump hierarchical loading third level takes every vacuum pump processing area 800 ~ 1000 squares or less, by that analogy, treat that sedimentation meets sedimentation in continuous 5 days and is not more than 2 millimeters, reach vacuum preloading and process requirement.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 1, it is characterized in that draining board includes the central layer of inside and the filter membrane that central layer is peripheral, drainage channel is formed between described central layer and filter membrane, described central layer is non-degradable material or difficult degradation material is made, and described filter membrane is that degradation material is made.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 4, it is characterized in that central layer includes the main gusset of a lateral arrangement and the many longitudinally spaced secondary gussets being arranged in before and after main gusset, main ribs plate, the space formed between secondary gusset and filter membrane are drainage channel.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 1, it is characterised in that described connecting tube is wired hose, and connecting tube includes the spiral wire of flexible pipe and Lining Hose.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 1, it is characterized in that house steward includes transverse tube, described transverse tube is formed by connecting by multiple transverse tube segmentations and manifold linkage section, is attached by manifold linkage section between adjacent two transverse tube segmentations.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 7, it is characterized in that manifold linkage section uses eight to lead to linkage section, eight lead to linkage section includes linkage section main body, the two ends, left and right of linkage section main body are respectively arranged with transverse tube segmentation interface, linkage section main body is forwardly and rearwardly respectively arranged with three connecting tube interfaces, the adjacent connecting tube of connecting tube interface is attached, and the adjacent transverse tube segmentation of transverse tube segmentation interface connects.

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 7, it is characterized in that described transverse tube segmentation includes a necking section and straight length, the distance of the necking section of same transverse tube segmentation to longitudinal tubule (L tubule) is than the distance of straight length to longitudinal tubule (L tubule).

A kind of ultra-soft foundation vacuum preloading seepage consolidation associating precipitating, pre-pressing concretion method the most according to claim 1, it is characterized in that house steward includes longitudinal tubule (L tubule), described longitudinal tubule (L tubule) is formed by connecting by multiple longitudinal tubule (L tubule) segmentations and three way cock, adjacent two longitudinal tubule (L tubule) segmentations are connected by three way cock, 3rd interface of three way cock connects the transverse tube closed on, and longitudinal tubule (L tubule) segmentation is additionally provided with check valve.