CN107023027A

CN107023027A - A kind of building concentration zones large-scale well-sinking construction method

Info

Publication number: CN107023027A
Application number: CN201710257042.7A
Authority: CN
Inventors: 田国印; 翟跃; 于海力; 呙佳
Original assignee: China Construction Sixth Engineering Division Co Ltd; China Construction Sixth Engineering Division Bridge Co Ltd
Current assignee: China Construction Sixth Engineering Division Co Ltd; China Construction Sixth Engineering Division Bridge Co Ltd
Priority date: 2017-04-19
Filing date: 2017-04-19
Publication date: 2017-08-08

Abstract

The invention discloses a kind of building concentration zones large-scale well-sinking construction method, a row hole drilling fender pile of first being constructed around open caisson, it is ensured that the security of Adjacent Buildings and the side friction for reducing the borehole wall, beneficial to sinking；Secondly progress sunk well foundation is excavated fills out with changing, and changes after tamping real groundwork bearing capacity satisfaction requirement and carries out steel caisson assembly；Then carry out concrete open caisson layering and connect height；Carry out well sinking finally by excavator+straddle truck+crawler crane combined machine mode of being unearthed, well sinking in accordance with " back in accurate positioning, elder generation, symmetrical layering are fetched earth, depth is appropriate " principle.The present invention solves the problem of building concentration zones large-scale well-sinking construction quality and open caisson Adjacent Buildings safety, while open caisson construction quality and safe Adjacent Buildings are ensured, improves efficiency of construction and reduces construction cost.

Description

A kind of building concentration zones large-scale well-sinking construction method

Technical field

The present invention relates to a kind of open caisson construction method, the invention particularly relates to a kind of applying for building concentration zones large-scale well-sinking Work method.

Background technology

With the fast development of science and construction technology, large-scale infrastructure projects is more and more, large-scale well-sinking should With also becoming widely.The research of large-scale well-sinking sinking construction in soft foundation comparative maturity, but up to the present There is no the case that large-scale well-sinking is used in bridge construction, when in building concentration zones, and the uneven area's open caisson of geology, well sinking During need to pass through more than 8m sand pebble layer, sand pebble layer side friction is big, and well sinking depth is big, sinks difficult, applies Work risk is larger, not yet has technical scheme to be referred at present.

The content of the invention

The present invention both protected to solve technical problem present in known technology there is provided a kind of construction method of large-scale well-sinking The safety and open caisson quality of open caisson Adjacent Buildings have been demonstrate,proved, efficiency of construction is improved again, construction cost is saved.

The present invention is adopted the technical scheme that to solve the technical problem that large-scale well-sinking construction is present：A kind of building collection Middle area's large-scale well-sinking construction method, it is characterised in that comprise the following steps：

(1) a circle cast-in-situ bored pile is made a call in the open caisson region 3-5m away from design, then leads to all drilled hole bored concrete pile top surface Linking beam connection is crossed to strengthen the resistance to overturning of cast-in-situ bored pile, described open caisson region is located at building concentrated area and heavy Need to pass through more than 8m sand pebble layer during underground is heavy；

(2) excavation of foundation pit is carried out in the region that cast-in-situ bored pile is surrounded, excavation of foundation pit depth is 3-4m；

(3) mixture of coarse sand or coarse sand and aggregate chips is backfilled in the range of cutting depth, replacement thickness is 3m-3.5m, Then Change and fill groundsill is rolled using rolled-on method, until the Change and fill groundsill bearing capacity after rolling meets design requirement；

(4) carry out borehole wall cutting shoe pit respectively to excavate and partition wall cutting shoe pit excavation, described borehole wall cutting shoe pit is opened Digging process is：Boundary in open caisson region excavates borehole wall cutting shoe pit continuously in a circumferential, is then pressed in borehole wall cutting shoe pit Multiple concrete pads are buried according to the location interval of the borehole wall cutting shoe of every section of borehole wall box hat to be installed, in concrete pad laying During, back-up sand is consolidated in the gap of concrete pad and cushion block groove, prevents cushion block lateral displacement；

Described partition wall cutting shoe pit digging process is：Open caisson region cross central line front and rear sides along parallel to The direction of cross central line and open caisson region longitudinal centre line the left and right sides along parallel to longitudinal centre line direction Partition wall cutting shoe pit, whole partition wall cutting shoe pit formation well shape structures are excavated respectively；Then in partition wall cutting shoe pit according to treating The location interval of the caisson cutting edge for the every section of mid-board box hat installed buries multiple concrete pads, is laid in concrete pad Cheng Zhong, back-up sand is consolidated in the gap of concrete pad and cushion block groove, prevents cushion block lateral displacement；

Described borehole wall cutting shoe pit and the bottom surface level of partition wall cutting shoe pit and the discrepancy in elevation of whole concrete pads No more than 3mm；

(5) between left and right partition wall cutting shoe pit and borehole wall cutting shoe pit and front and rear partition wall cutting shoe pit and borehole wall cutting shoe Excavated separately down in the middle of the top surface of Change and fill groundsill between pit and lay mortar bed, whole mortar bed formation well shape knots Structure, mortar bed top surface is set with Change and fill groundsill either flush；

(6) position being segmented in multistage borehole wall box hat and multistage mid-board box hat carries out the setting-out of terrestrial reference control point first, and Mark, then carries out steel caisson assembly according to mark position, and detailed process is as follows：

Step 1: according to first centre, then order all around is symmetrically installed positioned at sand successively in partition wall cutting shoe pit The multistage mid-board box hat of bed course well shape structure middle is starched, two sections of adjacent mid-board box hats are welded solid in installation process Fixed, the caisson cutting edge of every section of mid-board box hat is supported in multiple concrete pads；

Step 2: according to symmetry principle all around, side partition wall box hat is installed in lifting on mortar bed, and will be adjacent Two sections while partition wall box hat intersection and while partition wall box hat be weldingly connected with mid-board box hat intersection；

Step 3: being symmetrically installed multiple mid-boards positioned at mortar bed well shape structure outside in partition wall cutting shoe pit Multiple mid-board box hats are simultaneously weldingly connected by box hat with side partition wall box hat；

Step 4: carrying out borehole wall box hat according to symmetrical and symmetrical above and below principle segmentation in borehole wall cutting shoe pit Installation, and the borehole wall cutting shoe of every section of borehole wall box hat is supported in multiple concrete pads, adjacent two sections of borehole wall box hats it Between and the intersection of borehole wall box hat and mid-board box hat, side partition wall box hat be weldingly connected so that borehole wall box hat, mid-board box hat All it is weldingly connected with side partition wall box hat and is formed as one steel caisson；

In described borehole wall box hat, mid-board box hat and side partition wall box hat installation process, in correspondence per block concrete pad Paint marks are used on the box hat of block position；

After one section of borehole wall box hat of installation and mid-board box hat, in the partition wall cutting shoe pit and well for having concrete pad Sandbag revetment is used at wall cutting shoe pit, will be returned at without concrete pad with sand at partition wall cutting shoe pit and borehole wall cutting shoe pit Packing is real；

(7) concrete open caisson connects height, concretely comprises the following steps：(a) in described borehole wall box hat, mid-board box hat and side partition wall Difference embedded bar and the pre-buried air curtain pipeline in every side borehole wall box hat in box hat；(b) borehole wall box hat four angle points and Per the top surface middle of side borehole wall box hat, one observation station is set respectively；(c) to four since the mid-board box hat of steel caisson All symmetrical layerings pour steel caisson concrete in borehole wall box hat, mid-board box hat and side partition wall box hat, and coagulation is poured every time Level measurement is carried out in each observation station of open caisson before and after native, if differential settlement occurs for open caisson, suspends the side more than settlement of foundation Pouring for open caisson concrete, continues to pour open caisson concrete in the few side of settlement of foundation, until symmetrically being poured again after base stabilization Build；

(8) when steel caisson concrete；Reach after design strength 100%, it is first same to borehole wall box hat direction in the middle of open caisson When the symmetrical concrete for extracting vertical, horizontal mid-board box hat region concrete pad, then extracting the angular zone of borehole wall box hat four simultaneously Cushion block, then extracts the concrete pad of borehole wall box hat intermediate region, last to extract borehole wall remaining area concrete pad simultaneously； Often extract and sand pocket near the concrete pad is removed after a block concrete cushion block, and with sand backfilled cutting shoe pit closely knit；

(9) (c) step of described step (7) is repeated, connecing for next layer concrete open caisson is carried out successively high until arrival The height of well sinking requirement；

(10) from open caisson center to periphery is uniform, symmetrical, layering is fetched earth, and ensures the part insertion soil of each cutting shoe In；Open caisson, which fetches earth, to be concretely comprised the following steps：(a) by excavator by be arranged on the crawler crane on the outside of steel caisson be respectively symmetrically put into by In the open caisson wellhole in the centre position that borehole wall box hat, mid-board box hat and side partition wall box hat are surrounded；Then borehole wall box hat, in every Many straddle trucks are set on wall box hat and side partition wall box hat；(b) pan bottom shape is taken to take in each open caisson wellhole using excavator Soil, the soil then excavated using straddle truck handling, is finally had bad luck soil to Chang Nei mounds area using crawler crane, then will with transport vehicle Dregs transports to the Dumping Sites specified；(c) soil body in the symmetrical open caisson wellhole carried out at surrounding position of described step (b) is repeated Excavate；

Height of the height of the soil layer of the middle open caisson wellhole of described step (b) higher than soil layer in surrounding open caisson wellhole Soil layer highness change is within 0.5m scopes between 0.3m-0.4m, and each wellhole of surrounding open caisson wellhole；

(11) after the completion of soil excavation, open caisson starts to sink, when sinking, with sand backfill on the outside of borehole wall box hat with the soil body it Between gap, formed sand set, while observation it is each setting observation station at absolute altitude, if open caisson occur differential settlement, using sky Air curtain and sand set are rectified a deviation to open caisson, the risk that reduction open caisson can not sink in place, until well sinking is stable；

(12) described step (9)-(11) are repeated until steel caisson reaches design submergence depth.

The present invention has advantages below：

(1) it ensure that the safety of Adjacent Buildings；

(2) it ensure that the sinking of open caisson safety uniform；

(3) efficiency of construction is improved, construction cost has been saved.

Brief description of the drawings

Fig. 1 is the structural plan schematic diagram of steel caisson；

Fig. 2 is Fig. 1 A-A sectional schematic diagrams；

Fig. 3 is Fig. 1 B-B sectional schematic diagrams；

Fig. 4 is the assembled sequential schematic of steel caisson；

Fig. 5-1 is to backfill schematic diagram without the cutting shoe pit at concrete pad；

Fig. 5-2 is to have the cutting shoe pit backfill schematic diagram at concrete pad；

Fig. 6 is that first segment steel caisson concreting finishes schematic diagram；

Fig. 7 is that concrete open caisson connects high schematic diagram；

Fig. 8 is that open caisson fetches earth sinking floor map；

Fig. 9 is Fig. 8 C-C sectional drawings.

Embodiment

In order to be able to further appreciate that the invention, features and effects of the present invention, with reference to Fig. 1~Fig. 9 detailed construction methods It is described as follows：

A kind of construction method of large-scale well-sinking, comprises the following steps：

(1) a circle cast-in-situ bored pile is made a call in the open caisson region 3-5m away from design, then leads to all drilled hole bored concrete pile top surface Linking beam connection is crossed to strengthen the resistance to overturning of cast-in-situ bored pile, described open caisson region is located at building concentrated area and heavy Need to pass through more than 8m sand pebble layer during underground is heavy.

(2) excavation of foundation pit is carried out in the region that cast-in-situ bored pile is surrounded, excavation of foundation pit depth is 3-4m.

(3) mixture of coarse sand or coarse sand and aggregate chips is backfilled in the range of cutting depth, replacement thickness H is 3m-3.5m, Then Change and fill groundsill 7 is rolled using rolled-on method, until the bearing capacity of Change and fill groundsill 7 after rolling meets design requirement.

(4) carry out borehole wall cutting shoe pit respectively to excavate and partition wall cutting shoe pit excavation, described borehole wall cutting shoe pit is opened Digging process is：Boundary in open caisson region excavates borehole wall cutting shoe pit continuously in a circumferential, is then pressed in borehole wall cutting shoe pit Multiple concrete pads 5 are buried according to the location interval of the borehole wall cutting shoe 9 of every section of borehole wall box hat 8 to be installed, in concrete pad 5 In process of deployment, back-up sand is consolidated in the gap of concrete pad 5 and cushion block groove, prevents the lateral displacement of cushion block 5；

Described partition wall cutting shoe pit digging process is：Open caisson region cross central line front and rear sides along parallel to The direction of cross central line and open caisson region longitudinal centre line the left and right sides along parallel to longitudinal centre line direction Partition wall cutting shoe pit, whole partition wall cutting shoe pit formation well shape structures are excavated respectively；Then in partition wall cutting shoe pit according to treating The location interval of the caisson cutting edge 2 for the every section of mid-board box hat 1 installed buries multiple concrete pads 5, is spread in concrete pad 5 If during, back-up sand is consolidated in the gap of concrete pad 5 and cushion block groove, prevents the lateral displacement of cushion block 5；

The concrete pad 5 can using size as：Long 0.6m × wide 0.6m × high 0.25m, specific size presses practice of construction Depending on situation.

Described borehole wall cutting shoe pit and the bottom surface level of partition wall cutting shoe pit and the discrepancy in elevation of whole concrete pads 5 No more than 3mm.

It is preferred that the borehole wall cutting shoe pit slope gradient 4 be 1:1.25, such gradient is relatively delayed, and is not rushed with borehole wall cutting shoe Hit, it is to avoid slope soil slides.

It is preferred that the partition wall cutting shoe pit slope gradient 3 be 1:1, this avoid the landing of pit slope soil.

(5) between left and right partition wall cutting shoe pit and borehole wall cutting shoe pit and front and rear partition wall cutting shoe pit and borehole wall cutting shoe Excavated separately down in the middle of the top surface of Change and fill groundsill 7 between pit and lay mortar bed 6, the whole formation of mortar bed 6 wells Shape structure, the top surface of mortar bed 6 is set with the either flush of Change and fill groundsill 7；Laying mortar bed can avoid steel caisson from installing When be punched Change and fill groundsill 7, influence steel caisson installation accuracy.

(6) position being segmented in multistage borehole wall box hat 8 and multistage mid-board box hat 1 carries out the setting-out of terrestrial reference control point first, And mark, steel caisson assembly then is carried out according to mark position, referring to the direction shown in front in Fig. 4, detailed process is as follows：

Step 1: according to first centre, then order all around is symmetrically installed positioned at sand successively in partition wall cutting shoe pit The multistage mid-board box hat 1 of bed course well shape structure middle is starched, two sections of adjacent mid-board box hats are welded in installation process Fixed, the caisson cutting edge 2 of every section of mid-board box hat is supported in multiple concrete pads 5 that (cushion block particular number is with box hat length Depending on, longer quantity is more)；

As one embodiment of the present invention, mid-board box hat installation process is：

(a) first paragraph mid-board box hat 1 is transversely hung to the partition wall cutting shoe hole for standing on middle position using crawler crane In groove；

(b) second segment mid-board box hat 1 is hung along longitudinal direction using crawler crane and stands on the one of first paragraph mid-board box hat 1 Side；

(c) height and relative position of adjustment first paragraph mid-board box hat and second segment mid-board box hat 1, then by two sections Mid-board box hat is welded, and two sections of mid-board box hats is mutually perpendicular to and is vertically stood in partition wall cutting shoe pit；

(d) the crawler crane suspension hook on two sections of mid-board box hats 1 is unloaded, with a crawler crane by the 3rd section of mid-board box hat 1 hangs after the opposite side for standing on first paragraph mid-board box hat, adjustment position along longitudinal direction by the 3rd section of mid-board box hat and first paragraph Mid-board box hat 1 is welded, and is mutually orthogonal to one another three sections of mid-board box hats, as horizontal " work " font；

(e) section using horizontal " work " font box hat as the first positioning datum, repeat described step (a)-(d) install with It is symmetrical arranged before and after first positioning datum section and as three sections of mid-board box hats 1 of the second positioning datum section；

(f) in the front side and the left and right sides and the rear side in the second positioning datum section and left and right two of the first positioning datum section Mid-board box hat is respectively symmetrically installed in the partition wall cutting shoe pit of side, until by mortar bed well shape structure middle The installation of partition wall box hat 1.

Step 2: according to symmetry principle all around, side partition wall box hat 10 is installed in lifting on mortar bed 6, and will Adjacent two sections while the intersection of partition wall box hat 10 and while partition wall box hat 10 be weldingly connected with mid-board box hat intersection；

Step 3: being symmetrically installed multiple mid-boards positioned at mortar bed well shape structure outside in partition wall cutting shoe pit Multiple mid-board box hats 1 are simultaneously weldingly connected by box hat 1 with side partition wall box hat 10；

Step 4: carrying out borehole wall box hat according to symmetrical and symmetrical above and below principle segmentation in borehole wall cutting shoe pit 8 installation, and the borehole wall cutting shoe 9 of every section of borehole wall box hat 8 is supported in multiple concrete pads 5, two sections of adjacent borehole wall steel Between the shell 8 and intersection of borehole wall box hat 8 and mid-board box hat, side partition wall box hat 10 is weldingly connected so that borehole wall box hat 8, Mid-board box hat 1 and side partition wall box hat 10, which are all weldingly connected, is formed as one steel caisson；

In described borehole wall box hat 8, mid-board box hat 1 and the installation process of side partition wall box hat 10, in every piece of coagulation of correspondence Paint marks are used on the box hat of native cushion block position, facilitate the later stage to take out pad；

After one section of borehole wall box hat 8 of installation and mid-board box hat 1, there is the partition wall cutting shoe pit of concrete pad 5 With the bank protection of sand pocket 12 is used at borehole wall cutting shoe pit, facilitate the later stage to take out pad, with sand 11 by partition wall cutting shoe at without concrete pad 5 Backfill is closely knit at pit and borehole wall cutting shoe pit, to reduce backfill amount when taking out pad；

(7) concrete open caisson connects height, concretely comprises the following steps：(a) described borehole wall box hat 8, mid-board box hat 1 and side every Difference embedded bar 13 and the pre-buried air curtain pipeline in every side borehole wall box hat 8 in wall box hat 10；(b) the four of borehole wall box hat 8 The top surface middle of individual angle point and every side borehole wall box hat 8 sets an observation station respectively；(c) from the mid-board box hat of steel caisson 1 starts symmetrically to be layered to surrounding and pours steel caisson concrete in borehole wall box hat 8, mid-board box hat 1 and side partition wall box hat 10 14, so can be to open caisson load balance, it is to avoid have a negative impact to steel caisson structure, it is ensured that structure is steady, safety.Every time Level measurement is carried out in each observation station of open caisson before and after casting concrete, prevents that deviation of weight is excessive and it is uneven heavy ground occur Drop, if differential settlement occurs for open caisson, suspends pouring for the side open caisson concrete more than settlement of foundation, continues in settlement of foundation Few side pours open caisson concrete, until symmetrically being poured again after base stabilization.

(8) after steel caisson concrete 14 reaches design strength 100%, first to the direction of borehole wall box hat 8 in the middle of open caisson It is simultaneously symmetrical to extract the region concrete pad of vertical, horizontal mid-board box hat 1, then the mixed of the angular zone of borehole wall box hat 8 four is extracted simultaneously Solidifying soil cushion block, then extracts the concrete pad of the intermediate region of borehole wall box hat 8, last to extract borehole wall remaining area concrete simultaneously Cushion block.Often extract and sand pocket near the concrete pad is removed after a block concrete cushion block, and with sand backfilled cutting shoe pit close It is real；

(9) (c) step of described step (7) is repeated, next layer concrete open caisson is carried out successively (as the one of the present invention Kind of embodiment pour three layer concrete open caissons 15,16,17) connect high until reaching the height of well sinking requirement；

(10) from open caisson center to periphery is uniform, symmetrical, layering is fetched earth, and ensures that cutting shoe is not hanging as far as possible, each sword In the part insertion soil of pin；Open caisson, which fetches earth, to be concretely comprised the following steps：(a) excavator 20 is passed through into the shoe that is arranged on the outside of steel caisson Band hangs the 19 open caisson wells for being respectively symmetrically put into the centre position surrounded by borehole wall box hat 8, mid-board box hat 1 and side partition wall box hat 10 In hole；Then many straddle trucks 18 are set on borehole wall box hat 8, mid-board box hat 1 and side partition wall box hat 10；(b) using excavation Machine 20 takes pan bottom shape to fetch earth in each open caisson wellhole, it is ensured that the caisson cutting edge 2 of middle position provides enough supports Power, reduces the stress of the periphery borehole wall, and the soil then excavated using straddle truck handling is finally had bad luck soil to field using crawler crane 19 Interior mound area, then dregs is transported to the Dumping Sites specified with transport vehicle；(c) repeat described step (b) and symmetrically carry out surrounding position Put the excavation of the soil body in the open caisson wellhole at place；

Height of the height of the soil layer of the middle open caisson wellhole of described step (b) higher than soil layer in surrounding open caisson wellhole Soil layer highness change is within 0.5m scopes between 0.3m-0.4m, and each wellhole of surrounding open caisson wellhole.

(11) after the completion of soil excavation, open caisson starts to sink, when sinking, and the outside of borehole wall box hat 8 and the soil body are backfilled with sand Between gap, formed sand set, reduce part frictional resistance, while observation it is each setting observation station at absolute altitude, if open caisson occur not Uniform settlement, then rectified a deviation using air curtain and sand set to open caisson, the risk that reduction open caisson can not sink in place, until heavy Underground is sedate fixed.

The present invention solves the problem of large-scale well-sinking sinks difficult in building concentration zones, and construction method is safe and reliable, applies Work cost is substantially reduced, and suitable engineering is promoted the use of.

Embodiment 1

(1) a circle cast-in-situ bored pile is made a call in the open caisson region 4m away from design, then passes through all drilled hole bored concrete pile top surface Linking beam connection is to strengthen the resistance to overturning of cast-in-situ bored pile, and described open caisson region is located at building concentrated area and open caisson Need to pass through more than 8m sand pebble layer in sinking watching.

(2) excavation of foundation pit is carried out in the region that cast-in-situ bored pile is surrounded, excavation of foundation pit depth is 3.5m.

(3) mixture of coarse sand or coarse sand and aggregate chips is backfilled in the range of cutting depth, replacement thickness H is 3.5m, so Change and fill groundsill 7 is rolled using rolled-on method afterwards, until the bearing capacity of Change and fill groundsill 7 after rolling reaches 150Kpa.

The size of concrete pad 5 is：Long 0.6m × wide 0.6m × high 0.25m.

The described borehole wall cutting shoe pit slope gradient 4 is 1:1.25, the described partition wall cutting shoe pit slope gradient 3 is 1:1.

(6) position being segmented in multistage borehole wall box hat 8 and multistage mid-board box hat 1 carries out the setting-out of terrestrial reference control point first, And mark, steel caisson assembly then is carried out according to mark position, detailed process is as follows：

Step 1: according to first centre, then order all around is symmetrically installed positioned at sand successively in partition wall cutting shoe pit The multistage mid-board box hat 1 of bed course well shape structure middle is starched, two sections of adjacent mid-board box hats are welded in installation process Fixed, the caisson cutting edge 2 of every section of mid-board box hat is supported in 3 concrete pads 5；

Mid-board box hat installation process is：

Step 4: carrying out borehole wall box hat according to symmetrical and symmetrical above and below principle segmentation in borehole wall cutting shoe pit 8 installation, and the borehole wall cutting shoe 9 of every section of borehole wall box hat 8 is supported in 3 concrete pads 5, two sections of adjacent borehole wall box hats Between the 8 and intersection of borehole wall box hat 8 and mid-board box hat, side partition wall box hat 10 is weldingly connected so that borehole wall box hat 8, in Partition wall box hat 1 and side partition wall box hat 10, which are all weldingly connected, is formed as one steel caisson；

(9) repeat (c) step of described step (7), carry out pouring three layer concrete open caissons 15,16,17 successively until Reach the height of well sinking requirement；

Height of the height of the soil layer of the middle open caisson wellhole of described step (b) higher than soil layer in surrounding open caisson wellhole Soil layer highness change is within 0.5m scopes between 0.3mm, and each wellhole of surrounding open caisson wellhole.

Using this method can make the large-scale well-sinkings of building concentration zones in 9~12 meters of super thick sandy gravel smoothly under It is heavy.Provided with a circle cast-in-situ bored pile around open caisson, the ground of the surrounding building in open caisson soil excavation and sinking watching is protected Base.Pit and pad sand cushion block and sand bedding course are excavated in steel caisson partition wall and borehole wall cutting shoe region, it is ensured that pouring coagulation Soil stabilization before native at steel caisson cutting shoe, and then ensure that the integrally-built stabilization of steel caisson.In the middle of the borehole wall and corner Place is provided with 8 each observation station altogether, is monitored in real time in open caisson casting concrete and sinking watching, reaches and finds that open caisson is inclined in time Carry out tiltedly and in time the purpose of open caisson deviation rectification.It is unearthed using mini-excavator+straddle truck+crawler crane combination and coordinates air curtain and sand The construction method of the sinking of auxiliary is covered, compared with traditional construction method, well sinking is greatly ensure that smoothly, and significantly Accelerate speed of application, reduce construction cost.

Embodiment 2

(1) a circle cast-in-situ bored pile is made a call in the open caisson region 5m away from design, then passes through all drilled hole bored concrete pile top surface Linking beam connection is to strengthen the resistance to overturning of cast-in-situ bored pile, and described open caisson region is located at building concentrated area and open caisson Need to pass through more than 8m sand pebble layer in sinking watching.

(2) excavation of foundation pit is carried out in the region that cast-in-situ bored pile is surrounded, excavation of foundation pit depth is 3m.

(3) mixture of coarse sand or coarse sand and aggregate chips is backfilled in the range of cutting depth, replacement thickness H is 3m, then Change and fill groundsill 7 is rolled using rolled-on method, until the bearing capacity of Change and fill groundsill 7 after rolling reaches 150Kpa.

The size of concrete pad 5 is：Long 0.6m × wide 0.6m × high 0.25m.

Mid-board box hat installation process is：

Height of the height of the soil layer of the middle open caisson wellhole of described step (b) higher than soil layer in surrounding open caisson wellhole Soil layer highness change is within 0.5m scopes between 0.4mm, and each wellhole of surrounding open caisson wellhole.

Embodiment 3

(1) a circle cast-in-situ bored pile is made a call in the open caisson region 3m away from design, then passes through all drilled hole bored concrete pile top surface Linking beam connection is to strengthen the resistance to overturning of cast-in-situ bored pile, and described open caisson region is located at building concentrated area and open caisson Need to pass through more than 8m sand pebble layer in sinking watching.

(2) excavation of foundation pit is carried out in the region that cast-in-situ bored pile is surrounded, excavation of foundation pit depth is 4m.

(3) mixture of coarse sand or coarse sand and aggregate chips is backfilled in the range of cutting depth, replacement thickness H is 3.2m, so Change and fill groundsill 7 is rolled using rolled-on method afterwards, until the bearing capacity of Change and fill groundsill 7 after rolling reaches 150Kpa.

The size of concrete pad 5 is：Long 0.6m × wide 0.6m × high 0.25m.

Mid-board box hat installation process is：

Height of the height of the soil layer of the middle open caisson wellhole of described step (b) higher than soil layer in surrounding open caisson wellhole Soil layer highness change is within 0.5m scopes between 0.35mm, and each wellhole of surrounding open caisson wellhole.

The invention is not limited in above-mentioned embodiment, above-mentioned embodiment be only it is schematical, It is not restricted, one of ordinary skill in the art is not departing from present inventive concept and right under the enlightenment of the present invention It is required that under the ambit protected, can also make many forms, these are belonged within protection scope of the present invention.

Claims

1. a kind of building concentration zones large-scale well-sinking construction method, it is characterised in that comprise the following steps：

(1) a circle cast-in-situ bored pile is made a call in the open caisson region 3-5m away from design, then passes through all drilled hole bored concrete pile top surface even Binder connection is to strengthen the resistance to overturning of cast-in-situ bored pile, and described open caisson region is located under building concentrated area and open caisson Need to pass through more than 8m sand pebble layer during heavy；

(4) carry out borehole wall cutting shoe pit respectively to excavate and partition wall cutting shoe pit excavation, described borehole wall cutting shoe pit was excavated Cheng Wei：Boundary in open caisson region excavates borehole wall cutting shoe pit continuously in a circumferential, then in borehole wall cutting shoe pit according to treating The location interval of the borehole wall cutting shoe for the every section of borehole wall box hat installed buries multiple concrete pads, in concrete pad process of deployment In, back-up sand is consolidated in the gap of concrete pad and cushion block groove, prevents cushion block lateral displacement；

Described partition wall cutting shoe pit digging process is：Open caisson region cross central line front and rear sides along parallel to transverse direction The direction of center line and open caisson region longitudinal centre line the left and right sides along parallel to longitudinal centre line direction distinguish Excavate partition wall cutting shoe pit, whole partition wall cutting shoe pit formation well shape structures；Then according to be installed in partition wall cutting shoe pit The location interval of caisson cutting edge of every section of mid-board box hat bury multiple concrete pads, in concrete pad process of deployment In, back-up sand is consolidated in the gap of concrete pad and cushion block groove, prevents cushion block lateral displacement；

Described borehole wall cutting shoe pit and the bottom surface level of partition wall cutting shoe pit and the discrepancy in elevation of whole concrete pads does not surpass Cross 3mm；

(5) between left and right partition wall cutting shoe pit and borehole wall cutting shoe pit and front and rear partition wall cutting shoe pit and borehole wall cutting shoe pit Between Change and fill groundsill top surface in the middle of excavate separately down and lay mortar bed, whole mortar beds formation well shape structures, Mortar bed top surface is set with Change and fill groundsill either flush；

(6) position being segmented in multistage borehole wall box hat and multistage mid-board box hat carries out the setting-out of terrestrial reference control point first, and marks, Then steel caisson assembly is carried out according to mark position, detailed process is as follows：

Step 1: according to first centre, then order all around is symmetrically installed positioned at mortar pad successively in partition wall cutting shoe pit Two sections of adjacent mid-board box hats, are welded and fixed by the multistage mid-board box hat of layer well shape structure middle in installation process, The caisson cutting edge of every section of mid-board box hat is supported in multiple concrete pads；

Step 2: according to symmetry principle all around, side partition wall box hat is installed in lifting on mortar bed, and by adjacent two Section while partition wall box hat intersection and while partition wall box hat be weldingly connected with mid-board box hat intersection；

Step 3: being symmetrically installed multiple mid-board box hats positioned at mortar bed well shape structure outside in partition wall cutting shoe pit And multiple mid-board box hats are weldingly connected with side partition wall box hat；

Step 4: the peace of borehole wall box hat is carried out according to symmetrical and symmetrical above and below principle segmentation in borehole wall cutting shoe pit Dress, and the borehole wall cutting shoe of every section of borehole wall box hat is supported in multiple concrete pads, between two sections of adjacent borehole wall box hats with And the intersection of borehole wall box hat and mid-board box hat, side partition wall box hat is weldingly connected so that borehole wall box hat, mid-board box hat and side Partition wall box hat, which is all weldingly connected, is formed as one steel caisson；

In described borehole wall box hat, mid-board box hat and side partition wall box hat installation process, in correspondence per block concrete cushion block position Paint marks are used on the box hat put；

After one section of borehole wall box hat of installation and mid-board box hat, in the partition wall cutting shoe pit and borehole wall sword for having concrete pad Use sandbag revetment at pin pit, at without concrete pad with sand will at partition wall cutting shoe pit and borehole wall cutting shoe pit backfill it is close It is real；

(7) concrete open caisson connects height, concretely comprises the following steps：(a) in described borehole wall box hat, mid-board box hat and side partition wall box hat Interior embedded bar and the pre-buried air curtain pipeline in every side borehole wall box hat respectively；(b) in four angle points of borehole wall box hat and per side The top surface middle of borehole wall box hat sets an observation station respectively；(c) to surrounding pair since the mid-board box hat of steel caisson Before title layering pours steel caisson concrete, each casting concrete in borehole wall box hat, mid-board box hat and side partition wall box hat Level measurement is carried out in each observation station of open caisson afterwards, if differential settlement occurs for open caisson, suspends the side open caisson more than settlement of foundation Pouring for concrete, continues to pour open caisson concrete in the few side of settlement of foundation, until symmetrically being poured again after base stabilization；

(8) when steel caisson concrete；Reach after design strength 100%, it is first simultaneously right to borehole wall box hat direction in the middle of open caisson Claim to extract vertical, horizontal mid-board box hat region concrete pad, then extract the concrete pad of the angular zone of borehole wall box hat four simultaneously, Then the concrete pad of borehole wall box hat intermediate region is extracted, it is last to extract borehole wall remaining area concrete pad simultaneously；Often take out Except the sand pocket removed after a block concrete cushion block near the concrete pad, and it is with sand that the backfill of cutting shoe pit is closely knit；

(9) (c) step of described step (7) is repeated, connecing for next layer concrete open caisson is carried out successively high until arrival open caisson The height that sinking is required；

(10) from open caisson center to periphery is uniform, symmetrical, layering is fetched earth, and ensured in the part insertion soil of each cutting shoe； Open caisson, which fetches earth, to be concretely comprised the following steps：(a) excavator is respectively symmetrically put into by well by being arranged on the crawler crane on the outside of steel caisson In the open caisson wellhole in the centre position that wall box hat, mid-board box hat and side partition wall box hat are surrounded；Then in borehole wall box hat, mid-board Many straddle trucks are set on box hat and side partition wall box hat；(b) pan bottom shape is taken to fetch earth in each open caisson wellhole using excavator, Then the soil excavated using straddle truck handling, is finally had bad luck soil to Chang Nei mounds area using crawler crane, then with transport vehicle by slag Soil transports to the Dumping Sites specified；(c) soil body opens in the symmetrical open caisson wellhole carried out at surrounding position of step (b) described in repeating Dig；

Height 0.3m- of the height of the soil layer of the middle open caisson wellhole of described step (b) higher than soil layer in surrounding open caisson wellhole Soil layer highness change is within 0.5m scopes between 0.4m, and each wellhole of surrounding open caisson wellhole；

(11) after the completion of soil excavation, open caisson starts to sink, when sinking, and is backfilled with sand on the outside of borehole wall box hat between the soil body Gap, forms sand set, while the absolute altitude at each setting observation station of observation, if differential settlement occurs for open caisson, using air curtain And sand set is rectified a deviation to open caisson, the risk that reduction open caisson can not sink in place, until well sinking is stable；

2. building concentration zones large-scale well-sinking construction method according to claim 1, it is characterised in that：Described mid-board Box hat installation process is：

(a) first paragraph mid-board box hat is transversely hung in the partition wall cutting shoe pit for standing on middle position using crawler crane；

(b) second segment mid-board box hat is hung to the side for standing on first paragraph mid-board box hat using crawler crane along longitudinal direction；

(c) adjustment first paragraph mid-board box hat and second segment mid-board box hat height and relative position, then by two sections every Wall box hat is welded, and two sections of mid-board box hats is mutually perpendicular to and is vertically stood in partition wall cutting shoe pit；

(d) the crawler crane suspension hook on two sections of mid-board box hats is unloaded, it is with a crawler crane that the 3rd section of mid-board box hat edge is vertical By the 3rd section of mid-board box hat and first paragraph mid-board after the opposite side for standing on first paragraph mid-board box hat to hanging, adjustment position Box hat is welded, and is mutually orthogonal to one another three sections of mid-board box hats, as horizontal " work " font；

(e) section using horizontal " work " font box hat as the first positioning datum, repeats described step (a)-(d) and installs and first It is symmetrical arranged before and after positioning datum section and as three sections of mid-board box hats of the second positioning datum section；

(f) in the front side and the left and right sides and the rear side in second positioning datum section and the left and right sides of the first positioning datum section Mid-board box hat is respectively symmetrically installed in partition wall cutting shoe pit, until by positioned at the mid-board of mortar bed well shape structure middle Box hat installation.

3. the building concentration zones large-scale well-sinking construction method according to claims 1 or 2, it is characterised in that：Described The borehole wall cutting shoe pit slope gradient is 1:1.25.

4. the building concentration zones large-scale well-sinking construction method according to claims 1 or 2, it is characterised in that：Described The partition wall cutting shoe pit slope gradient is 1:1.