CN105113511A - Comprehensive foundation pit support construction method for sandstone combined soil layer - Google Patents

Comprehensive foundation pit support construction method for sandstone combined soil layer Download PDF

Info

Publication number
CN105113511A
CN105113511A CN201510425754.6A CN201510425754A CN105113511A CN 105113511 A CN105113511 A CN 105113511A CN 201510425754 A CN201510425754 A CN 201510425754A CN 105113511 A CN105113511 A CN 105113511A
Authority
CN
China
Prior art keywords
layer
sand
well
points dewatering
excavation
Prior art date
Application number
CN201510425754.6A
Other languages
Chinese (zh)
Other versions
CN105113511B (en
Inventor
张宝建
Original Assignee
河北二十冶建设有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 河北二十冶建设有限公司 filed Critical 河北二十冶建设有限公司
Priority to CN201510425754.6A priority Critical patent/CN105113511B/en
Publication of CN105113511A publication Critical patent/CN105113511A/en
Application granted granted Critical
Publication of CN105113511B publication Critical patent/CN105113511B/en

Links

Abstract

The invention provides a comprehensive foundation pit support construction method for a sandstone combined soil layer. The method comprises specific steps as follows: a, a clay layer on the upper layer is subjected to earth excavation, and a plurality of oblique inserting type well point dewatering pipes and a plurality of vertical type well point dewatering pipes are alternately mounted on a sand layer after excavation is performed to the sand layer; b, the oblique inserting type well point dewatering pipes and the vertical type well point dewatering pipes are operated simultaneously; c, excavation is continuously performed after water level of underground water in the sand layer is decreased to a reserved elevation, and dense steel screens are paved at the lower part of the sand layer and soil nails are adopted for anchoring after the excavation is performed to a rock layer; d, rocks of the rock layer are chiseled, and earth excavation is performed continuously; e, broken stones after chiseling are removed, and structural construction is performed. According to the method, a support mode of combination of light dewatering wells and dense steel screen anchoring is adopted, underground water in the sand layer can be drained in time, the safety of the foundation pit support process is improved, and the difficulty of foundation pit excavation is reduced. The support technology is simpler, the support cost is reduced, and the construction time is shortened.

Description

Sandstone is in conjunction with the foundation ditch comprehensive support construction method of soil layer
Technical field
The present invention relates to a kind of construction method of pattern foundation pit supporting structure, specifically a kind of sandstone is in conjunction with the foundation ditch comprehensive support construction method of soil layer.
Background technology
According to the growing tension of Practical Project construction needs and construction land, Engineering Construction Land-Occupation selected areas is gradually near riverine, coastal and beach region, and this type of region mostly is the stratum that sandstone combines.Therefore, need from top to bottom during excavation of foundation pit successively through argillic horizon, layer of sand and lithosphere, because middle layer of sand water content is high, water source is more sufficient, and basic unit's excavation there will be large area drift sand phenomenon through layer of sand, causes foundation ditch to excavate smoothly.If dewatering construction, then can not possess water permeability because of lithosphere, well-points dewatering pipe is fit into lithosphere can be more difficult, cannot thoroughly tackle the underground water being penetrated into institute's excavation pit by layer of sand, cause instability of foundation pit to cave in, hinder carrying out smoothly of foundation pit construction.
For the stratum characteristic that this kind of sandstone combines, selectable support pattern is limited.The patent No. is that the patent of invention of 201410828811.0 is for this orographic condition, Construction of High Pressure Jet Grouting Pile is done outside foundation pit supporting system, a jet grouting pile construction is utilized to reach the effect that tentatively intercepts water, carry out soldier pile construction again, start secondary jet grouting pile construction subsequently, in the mode of combination construction, steel mesh reinforcement is coordinated to spray open drain in slope protection construction and foundation ditch, collecting well, catch pit construction, successfully solve the difficult problem of pattern foundation pit supporting structure under the geological environment that sandstone combines, but the work progress of this support pattern is comparatively complicated, and the construction period is longer.
Summary of the invention
Object of the present invention is just to provide the foundation ditch comprehensive support construction method of a kind of sandstone in conjunction with soil layer, to solve the problem that in prior art, foundation pit support construction is comparatively complicated and the construction period is longer in the soil layer environment of sandstone combination.
The present invention is achieved in that
Sandstone, in conjunction with a foundation ditch comprehensive support construction method for soil layer, comprises the following steps:
A, carry out soil excavation to the argillic horizon on upper strata, dig and stop excavation of earthwork work after there is layer of sand, the horizontal directions of the layer of sand around foundation ditch is for installing some oblique inserting well-points dewatering pipes and some rectilinear well-points dewatering pipes;
B, simultaneously operation oblique inserting well-points dewatering pipe and rectilinear well-points dewatering pipe: utilize oblique inserting well-points dewatering pipe to tackle the underground water of layer of sand and lithosphere interface, utilize the underground water in rectilinear well-points dewatering pipe interception layer of sand;
C, after in layer of sand, the water level of underground water drops to predetermined absolute altitude, to foundation ditch carry out next step excavation, be excavated to after there is lithosphere, around foundation ditch, the bottom of layer of sand is laid close order expanded metal lath and is carried out anchoring with soil nailing;
D, work is cut to the rock of lithosphere, continue earth excavation;
Rubble after e, removing cut, carries out structure construction.
Described oblique inserting well-points dewatering pipe and rectilinear well-points dewatering pipe are Application of light well point precipitation pipe; The bottom of described oblique inserting well-points dewatering pipe is provided with short chimney filter, the bottom of described rectilinear well-points dewatering pipe is provided with long chimney filter, the length of described long chimney filter is 3 times ~ 6 times of the length of described short chimney filter.
Described oblique inserting well-points dewatering pipe is tilted to foundation ditch lateral direction the intersection being inserted into layer of sand and lithosphere from the top of layer of sand, and described rectilinear well-points dewatering pipe is inserted into the intersection of layer of sand and lithosphere downwards with the direction of vertical layer of sand end face from the top of layer of sand.
When carrying out anchoring with described soil nailing to described close order expanded metal lath, be wedged into lithosphere in from the upper part of close order expanded metal lath through layer of sand by described soil nailing, the termination of described soil nailing is connected with described close order expanded metal lath.
The layer of sand of the present invention around foundation ditch is alternately installed some oblique inserting Application of light well point precipitation pipes and some rectilinear Application of light well point precipitation pipes, the bottom of oblique inserting well-points dewatering pipe is provided with short chimney filter, the bottom of rectilinear well-points dewatering pipe is provided with long chimney filter, the length of long chimney filter is 3 times ~ 6 times of the length of short chimney filter, what the bottom due to oblique inserting well-points dewatering pipe was arranged is short chimney filter, and be in the bottom of layer of sand, fully can tackle the underground water of layer of sand and lithosphere interface.What the bottom due to rectilinear well-points dewatering pipe was arranged is long chimney filter, comparatively large with the contact area of layer of sand, fully can tackle most underground water in layer of sand, carry out drainage to layer of sand.Around foundation ditch, the bottom of layer of sand is laid close order expanded metal lath and is carried out anchoring with soil nailing, the mounting process of close order expanded metal lath is comparatively simple, can effectively prevent caving in of layer of sand, and close order expanded metal lath also has the effect of drainage and shutoff earth, can moisture in layer of sand be incorporated in foundation ditch, then discharge.
The present invention effectively can solve the problem of supporting difficulty in excavation of foundation pit under the geological conditions that sandstone combines, take the support pattern that light-duty dewatering well combines with the anchoring of close order expanded metal lath, can underground water in time in drainage layer of sand, prevent slope instability from causing cave-in accident, improve the safety of pattern foundation pit supporting structure process, reduce the difficulty of excavation of foundation pit.Its support process is comparatively simple, reduces support cost, shortens the engineering time.
Accompanying drawing explanation
Fig. 1 is the structural representation of pattern foundation pit supporting structure of the present invention.
Fig. 2 is the structural representation of foundation ditch medial surface.
In figure: 1, argillic horizon, 2, layer of sand, 3, lithosphere, 4, oblique inserting well-points dewatering pipe, 4-1, short chimney filter, 5, rectilinear well-points dewatering pipe, 5-1, long chimney filter, 6, close order expanded metal lath, 7, soil nailing.
Detailed description of the invention
As depicted in figs. 1 and 2, the concrete steps of foundation ditch comprehensive support construction method of the present invention are:
(1) carry out soil excavation to the argillic horizon 1 on upper strata, dig and stop excavation of earthwork work after there is layer of sand 2, the horizontal directions of the layer of sand 1 around foundation ditch is for installing some oblique inserting well-points dewatering pipes 4 and some rectilinear well-points dewatering pipes 5.
(2) run oblique inserting well-points dewatering pipe 4 and rectilinear well-points dewatering pipe 5: utilize oblique inserting well-points dewatering pipe 4 to tackle the underground water of layer of sand 2 and lithosphere 3 interface simultaneously, utilize rectilinear well-points dewatering pipe 5 to tackle underground water in layer of sand 2.
(3) after in layer of sand 2, the water level of underground water drops to predetermined absolute altitude, carry out next step excavation to foundation ditch, be excavated to after there is lithosphere 3, around foundation ditch, the bottom of layer of sand 2 is laid close order expanded metal lath 6 and is carried out anchoring with soil nailing 7.
(4) work is cut to the rock of lithosphere 3, continue earth excavation.
(5) remove the rubble after cutting, carry out structure construction.
What the present invention adopted excavation of foundation pit is stage excavation mode.
As depicted in figs. 1 and 2, oblique inserting well-points dewatering pipe 4 and rectilinear well-points dewatering pipe 5 are Application of light well point precipitation pipe.Be provided with short chimney filter 4-1 in the bottom of oblique inserting well-points dewatering pipe 4, be provided with long chimney filter 5-1 in the bottom of rectilinear well-points dewatering pipe 5, the length of long chimney filter 5-1 is 3 times ~ 6 times of the length of short chimney filter 4-1.Oblique inserting well-points dewatering pipe 4 is tilted to the intersection being inserted into layer of sand 2 and lithosphere 3 from the top of layer of sand 2 to foundation ditch lateral direction, rectilinear well-points dewatering pipe 5 is inserted into the intersection of layer of sand 2 and lithosphere 3 downwards with the direction of vertical layer of sand 2 end face from the top of layer of sand 2.Because layer of sand 2 water content is more, easily produce drift sand phenomenon, in the process of Support of Foundation Pit Excavation, adopt well-points dewatering can moisture in time in drainage layer of sand 2, prevent slope instability cave-in accident.Because the short chimney filter 4-1 of oblique inserting well-points dewatering pipe 4 lower end is near the intersection of layer of sand 2 with lithosphere 3, can tackle in time and the underground water of drainage layer of sand 2 and lithosphere 3.Due to rectilinear well-points dewatering pipe 5 lower end long chimney filter 5-1 and the contact area of layer of sand 2 comparatively large, can underground water in the interception layer of sand 2 of maximum magnitude.
Before soil nailing 7 is constructed, need strictly to require that making position, hole carries out mark according to support design of slope, when anchoring being carried out to close order expanded metal lath 6 with soil nailing 7, soil nailing 7 is wedged in lithosphere 3 from the upper part of close order expanded metal lath 6 through layer of sand 2, the termination of soil nailing 7 is connected with close order expanded metal lath 6, the body of rod of soil nailing 7 and the wire side of close order expanded metal lath 6 form an angle, and the scope of angle is 60 ° ~ 90 °.The termination of soil nailing 7 adopts the mode of screw threads for fastening and close order expanded metal lath 6 to carry out fastening.Connection between close order expanded metal lath 6 can adopt the form of overlap joint, and also can adopt spot welding and make use of momentum the mode of laying with layer of sand domatic, that the present invention adopts is the latter, i.e. spot welding with the domatic mode of laying of making use of momentum of layer of sand.
The present invention is applicable to the construction method of sandstone in conjunction with the foundation ditch comprehensive support under soil layer, and construction method is simple, can reduce construction cost.

Claims (4)

1. sandstone is in conjunction with a foundation ditch comprehensive support construction method for soil layer, it is characterized in that, comprises the following steps:
A, carry out soil excavation to the argillic horizon on upper strata, dig and stop excavation of earthwork work after there is layer of sand, the horizontal directions of the layer of sand around foundation ditch is for installing some oblique inserting well-points dewatering pipes and some rectilinear well-points dewatering pipes;
B, simultaneously operation oblique inserting well-points dewatering pipe and rectilinear well-points dewatering pipe: utilize oblique inserting well-points dewatering pipe to tackle the underground water of layer of sand and lithosphere interface, utilize the underground water in rectilinear well-points dewatering pipe interception layer of sand;
C, after in layer of sand, the water level of underground water drops to predetermined absolute altitude, to foundation ditch carry out next step excavation, be excavated to after there is lithosphere, around foundation ditch, the bottom of layer of sand is laid close order expanded metal lath and is carried out anchoring with soil nailing;
D, work is cut to the rock of lithosphere, continue earth excavation;
Rubble after e, removing cut, carries out structure construction.
2. sandstone according to claim 1 is in conjunction with the foundation ditch comprehensive support construction method of soil layer, it is characterized in that, described oblique inserting well-points dewatering pipe and rectilinear well-points dewatering pipe are Application of light well point precipitation pipe; The bottom of described oblique inserting well-points dewatering pipe is provided with short chimney filter, the bottom of described rectilinear well-points dewatering pipe is provided with long chimney filter, the length of described long chimney filter is 3 times ~ 6 times of the length of described short chimney filter.
3. sandstone according to claim 1 and 2 is in conjunction with the foundation ditch comprehensive support construction method of soil layer, it is characterized in that, described oblique inserting well-points dewatering pipe is tilted to foundation ditch lateral direction the intersection being inserted into layer of sand and lithosphere from the top of layer of sand, and described rectilinear well-points dewatering pipe is inserted into the intersection of layer of sand and lithosphere downwards with the direction of vertical layer of sand end face from the top of layer of sand.
4. sandstone according to claim 1 is in conjunction with the foundation ditch comprehensive support construction method of soil layer, it is characterized in that, when anchoring being carried out to described close order expanded metal lath with described soil nailing, be wedged into lithosphere in from the upper part of close order expanded metal lath through layer of sand by described soil nailing, the termination of described soil nailing is connected with described close order expanded metal lath.
CN201510425754.6A 2015-07-20 2015-07-20 Sandstone combines the foundation ditch comprehensive support construction method of soil layer CN105113511B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510425754.6A CN105113511B (en) 2015-07-20 2015-07-20 Sandstone combines the foundation ditch comprehensive support construction method of soil layer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510425754.6A CN105113511B (en) 2015-07-20 2015-07-20 Sandstone combines the foundation ditch comprehensive support construction method of soil layer

Publications (2)

Publication Number Publication Date
CN105113511A true CN105113511A (en) 2015-12-02
CN105113511B CN105113511B (en) 2016-11-30

Family

ID=54661603

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510425754.6A CN105113511B (en) 2015-07-20 2015-07-20 Sandstone combines the foundation ditch comprehensive support construction method of soil layer

Country Status (1)

Country Link
CN (1) CN105113511B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106801427A (en) * 2016-12-15 2017-06-06 宁波二十冶建设有限公司 Foundation ditch horizontal precipitation device and its application method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000136539A (en) * 1998-10-30 2000-05-16 Nishimatsu Constr Co Ltd Ground excavating method
CN102162250A (en) * 2010-02-24 2011-08-24 中国二十冶集团有限公司 Protective construction method of excavating large area deep foundation pit in running sand confined water soil layer
CN104612162A (en) * 2014-12-15 2015-05-13 中铁二十局集团第三工程有限公司 Subway station deep foundation pit excavation construction method
CN104631470A (en) * 2014-12-26 2015-05-20 合肥建工集团有限公司 Deep foundation pit combination retaining and protecting construction method for geology with high water level and large particle size sand gravel

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000136539A (en) * 1998-10-30 2000-05-16 Nishimatsu Constr Co Ltd Ground excavating method
CN102162250A (en) * 2010-02-24 2011-08-24 中国二十冶集团有限公司 Protective construction method of excavating large area deep foundation pit in running sand confined water soil layer
CN104612162A (en) * 2014-12-15 2015-05-13 中铁二十局集团第三工程有限公司 Subway station deep foundation pit excavation construction method
CN104631470A (en) * 2014-12-26 2015-05-20 合肥建工集团有限公司 Deep foundation pit combination retaining and protecting construction method for geology with high water level and large particle size sand gravel

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106801427A (en) * 2016-12-15 2017-06-06 宁波二十冶建设有限公司 Foundation ditch horizontal precipitation device and its application method
CN106801427B (en) * 2016-12-15 2019-05-28 宁波二十冶建设有限公司 Foundation pit horizontal precipitation device and its application method

Also Published As

Publication number Publication date
CN105113511B (en) 2016-11-30

Similar Documents

Publication Publication Date Title
CN100464055C (en) Construction method of shallow buried underground excavating tunnel super large section using PBA method
CN105422170B (en) Middle deep goaf grouting reinforcing and processing method under a kind of building foundation
CN103306687B (en) Soft rock tunnel long cantilever horizontal jet grouting Deformation control construction method
CN104863629B (en) A kind of method taking out absciss layer gas and draining slip casting under overlying strata using combined drilling and counterboring
CN104694746B (en) A kind of method of ion adsorption type re in_situ leaching and leaching ore deposit system thereof
CN104612695B (en) One acutely collapses shaft wall restoring and fastening method
CN104929666A (en) Top breaking gob-side entry retaining method for tender roofs
CN102493822B (en) Method for performing curtain grouting construction on tunnel by water rich fault influence zone
CN104612162B (en) A kind of Deep Foundation Pit of Metro Stations excavation construction method
CN106121657B (en) A kind of multifunctional numerical control shaft sinking device and construction method
CN105257301B (en) A kind of shallow-depth-excavation tunnel weak surrounding rock landslide reinforcing and processing method
CN102505695B (en) Construction method for deep foundation pit of three-dimensional garage
CN105298507B (en) A kind of underground pipe gallery construction method of top open cut bottom tunneler construction
CN102251777B (en) Large-scale karst cavity treatment method for karst tunnel
CN204253054U (en) Mountain tunnel stake arch cap excavation method comprehensive support structure
CN102418347B (en) Drainage construction method for blind drain and sump wells in deep foundation pit
CN104847355A (en) Continuous mining method of medium-thick heavy pitch ore body empty field
CN103882881B (en) Go deep into rock construction method under water
CN102182472B (en) Backfill repairing method for tunnel collapse cavity
CN103206219A (en) Holed excavation supporting structure for light and dark junction section of tunnel in bias pressure state and construction method
CN104032758B (en) Extra-high reinforced construction method in discarded pit
CN104532818A (en) Treatment method for strip mine goaf
CN104131829B (en) A kind of solid filling coal mining hydraulic supporting building and withdrawing frame method
CN104947690B (en) Grooving construction method for embedding underground continuous wall into rock
Cui et al. Mitigation of geohazards during deep excavations in karst regions with caverns: a case study

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant