CN218479174U - Compound retaining structure of deep basal pit - Google Patents

Abstract

The utility model provides a deep foundation pit composite enclosure structure, which comprises a water intercepting system, a supporting beam system, an anchor cable system and a drainage system, wherein the supporting beam system and the anchor cable system are used for supporting the inside of the deep foundation pit and accelerating the construction progress; the water intercepting system divides the water intercepting work of the deep foundation pit into an overground part and an underground part, the overground part comprises ground drainage ditches which are preset on the periphery of the deep foundation pit before the deep foundation pit is excavated, and the underground part encloses and forms the preset shape of the deep foundation pit; the supporting beam system comprises an upper structure and a lower structure which are arranged one by one in the process of excavating the deep foundation pit, and the upper structure encloses the top of the deep foundation pit through a crown beam; the utility model discloses a set up the foundation ditch retaining structure of a combined type, utilize soil cement mixing pile, shaped steel, a supporting beam, anchor rope to carry out safety protection to the deep basal pit side slope, guaranteed deep basal pit's stability, security.

Description

Compound retaining structure of deep basal pit

Technical Field

The utility model relates to a deep basal pit struts engineering technical field, concretely relates to compound retaining structure of deep basal pit.

Background

With the acceleration of the urbanization process, the new construction, reconstruction and extension projects of urban areas are continuously increased, the scale of a single project is continuously enlarged, the underground space required by a building is larger and larger in scale and deeper, and the deep foundation pit project is produced at the right moment. In the process of deep foundation pit construction and underground main structure construction, how to ensure the safety and stability of the deep foundation pit in the process of underground building construction becomes a problem that people must face, if the deep foundation pit engineering is not reliably supported, in the later-stage underground main structure construction process, the damage of instability, collapse, subsidence and the like of the deep foundation pit is easily caused, great economic loss is caused, safety accidents can be caused in serious cases, the lives of personnel are damaged, and adverse effects are brought to the country and the society.

In addition, due to the characteristics of large excavation depth and complex underground environment of deep foundation pit engineering, the bottom of the foundation pit is usually below the underground water level, the periphery of the foundation pit is within the influence range of the underground water, and the seepage prevention problem of the deep foundation pit is also a difficult problem to be faced by engineering personnel.

The traditional support member for the deep foundation pit support structure mostly adopts a reinforced concrete structure, the method relates to the working procedures of binding steel bars, supporting templates, pouring concrete, maintaining and the like, the consumption period is long, the support effect on the support structure cannot be timely realized, the construction influence on the next working procedure is large, and the engineering construction progress is greatly prolonged.

Therefore, it is necessary to provide a reasonable, reliable and fast-constructed enclosure structure for deep foundation pit engineering, so as to provide a good construction environment for subsequent underground and overground main structure construction, and improve the safety and stability of deep foundation pit construction.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a composite enclosure structure for supporting and anti-seepage treatment of a deep foundation pit, providing a good construction environment for the subsequent underground and overground main structure construction and improving the safety of the deep foundation pit construction,

therefore, the utility model adopts the following technical proposal:

a composite enclosure structure for a deep foundation pit comprises a water intercepting system, a supporting beam system, an anchor cable system and a drainage system, wherein the supporting beam system supports the interior of the deep foundation pit and can accelerate the construction progress; the water intercepting system divides the water intercepting work of the deep foundation pit into an overground part and an underground part, the overground part comprises ground drainage ditches which are preset on the periphery of the deep foundation pit before the deep foundation pit is excavated, and the underground part encloses and forms the preset shape of the deep foundation pit; the supporting beam system comprises an upper structure and a lower structure which are arranged one by one in the process of excavating the deep foundation pit, the upper structure is used for enclosing the top of the deep foundation pit through a crown beam, the upper structure is connected with the top of the underground part, and the lower structure is arranged at the waist of the deep foundation pit and is used for enclosing the periphery of the deep foundation pit through a waist beam; the crown beam and the waist beam are supported and connected through a detachable inclined strut rigid beam and a detachable cross strut rigid beam; the drainage system comprises a foundation pit drainage ditch which is formed by digging on the bottom surface of the deep foundation pit, and the foundation pit drainage ditch is arranged along the wall of the deep foundation pit.

Further, the method comprises the following steps: the overground part also comprises a side slope, the side slope is arranged between the ground drainage ditch and the crown beam, and a gap is formed between the side slope and the ground drainage ditch; the side slope sets gradually reinforcing bar net and sprayed concrete layer outwards by ground, the slope is interior to insert to one side and is provided with the outlet pipe, just the outlet pipe orientation deep basal pit direction sets up, the outlet pipe wraps up in outward has the filter screen.

Further: the underground part comprises a cement soil mixing pile and section steel; the cement-soil mixing piles are arranged around the deep foundation pit, and the crown beam is connected with the top of the cement-soil mixing pile and the section steel (3); the profile steel is inserted into the deep foundation pit, arranged in the cement-soil mixing pile and protruded out of the top of the profile steel.

Further: the crown beam and the waist beam are connected with the inclined strut rigid beam and the cross strut rigid beam in a mode of adding bolts to anchor plates; both ends of the single side of the crown beam and the waist beam are provided with reinforced concrete inclined pad platforms; the anchor plates are pre-embedded in the table top of the reinforced concrete inclined pad table, a first inclined strut rigid beam is arranged between the reinforced concrete inclined pad tables at the same corner, the anchor plates are arranged at the two end parts of the first inclined strut rigid beam, a stiffening steel plate is arranged between the first inclined strut rigid beam and the anchor plate on the first inclined strut rigid beam, and the first inclined strut rigid beam and the reinforced concrete inclined pad tables at the same corner are respectively connected on the anchor plates through bolts; the anchor plates are respectively arranged at the two end parts of the first cross brace rigid beam and the contact side surface of the crown beam, the stiffening steel plate is also arranged between the first cross brace rigid beam and the anchor plate on the first cross brace rigid beam, and the first cross brace rigid beam and the contact side surface of the crown beam are respectively connected on the anchor plate through the bolts; the adjacent limit of waist rail is passed through the second and is said the connection of bracing rigid beam, just the connection mode of the second way bracing rigid beam with crown the roof beam is last the connection mode of the first way bracing rigid beam is unanimous, the relative limit of waist rail is passed through the connection of the second way bracing rigid beam, just the connection mode of the second way bracing rigid beam with crown the roof beam is last the connection mode of the first way bracing rigid beam is unanimous.

Further, the method comprises the following steps: the anchor cable system is distributed around the deep foundation pit and comprises anchor cables and anchoring devices; the anchor cable is divided into a first part, a second part and a third part according to the construction depth progress; the first part comprises a first anchor cable and a first anchor cable anchoring section, the second part comprises a second anchor cable and a second anchor cable anchoring section, and the third part comprises a third anchor cable and a third anchor cable anchoring section; the first anchor cable is obliquely and downwards arranged on the crown beam, and the anchoring section of the first anchor cable is obliquely inserted into the soil body; the second anchor cable is obliquely and downwards arranged between the crown beam and the waist beam, the second anchor cable is arranged on the pit wall of the deep foundation pit, and the anchoring section of the second anchor cable is obliquely inserted into the soil body; the third anchor cable is obliquely and downwards arranged on the waist beam, and the anchoring section of the third anchor cable is obliquely inserted into the soil body; and the lengths of the first anchor cable, the second anchor cable and the third anchor cable are shortened one by one.

Further, the method comprises the following steps: the anchoring device comprises a locking piece arranged on the anchor cable, and an anchorage device, a channel steel, an anchor backing plate and an inclined iron backing plate which are independently arranged on the second anchor cable; the locking piece is arranged on the free section of the anchor cable and used for locking the tensioned anchor cable; the inclined sizing block is arranged on the pit wall of the deep foundation pit, the inclined sizing block is arranged in an inclined mode at the same angle with the second anchor cable, and a hole is preset in the inclined sizing block; the channel steel is arranged on the inclined sizing block, and a gap is reserved between the channel steel; the anchor backing plate is arranged on the channel steel; the anchorage device is arranged on the anchor backing plate; and forming a penetrating and pulling channel of the anchor cable through a gap between the channel steels and the hole in the inclined sizing block.

Further: the drainage system also comprises a foundation pit water collecting well; the foundation ditch sump pit is located the foundation ditch escape canal, the inside grade that sets up in foundation ditch escape canal, and domatic orientation the foundation ditch sump pit.

Further: the drainage system also comprises a foundation pit dewatering well which is continuously deepened in the excavation process of the deep foundation pit; the foundation pit dewatering well is arranged in the bottom surface of the deep foundation pit and comprises a gravel filtering layer, a well washing pipe, a steel pipe, a submersible pump and a water outlet pipe; the gravel filter layer is arranged on the outermost layer of the foundation pit dewatering well in the soil body; the steel pipe is arranged on the inner side of the gravel filtering layer; the submersible pump is arranged in the steel pipe; the well washing pipe is arranged in the gravel filter layer and positioned on the outer side of the steel pipe, and the insertion depth of the well washing pipe is consistent with the depth of the submersible pump; the water outlet pipe is connected with the submersible pump, and the length of the water outlet pipe is larger than that of the steel pipe.

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model discloses a set up the foundation ditch retaining structure of a combined type, utilize soil cement mixing pile, shaped steel, a supporting beam, anchor rope to carry out safety protection to the deep basal pit side slope, guaranteed deep basal pit's stability, security. Additionally, the utility model discloses utilize envelope and water-intercepting system, the drainage system that cement mixing pile and shaped steel are constituteed, effectively solved deep basal pit prevention of seepage problem, avoided the adverse effect of groundwater in the deep basal pit work progress, provide good construction environment for the major structure construction. The utility model discloses a set up the bolted connection of prefabricated girder steel and guan liang, waist rail, reduce the rate of utilization that adopts reinforced concrete structure, accelerated greatly and adopted whole reinforced concrete structure's construction progress and enclosure cycle relatively, in time accomplished foundation ditch support beam system simultaneously, guaranteed safety, the stability of foundation ditch.

Drawings

Fig. 1 is the utility model discloses the compound envelope plane arrangement schematic diagram of deep basal pit.

Fig. 2 is the utility model discloses deep basal pit composite envelope section sketch map.

Fig. 3 is a schematic plan view of the first support beam of the present invention.

Fig. 4 is a schematic plan view of a second supporting beam according to the present invention.

Fig. 5 is a schematic view of the connection between the cross brace and the crown beam of the present invention.

Fig. 6 is a schematic view of the connection between the inclined strut and the crown beam of the present invention.

Fig. 7 is a schematic view of the anchoring device of the present invention.

Figure 8 is a schematic sectional view of the dewatering well of the present invention.

Figure 9 is a schematic plan view of the dewatering well of the utility model.

Fig. 10 is a schematic sectional view of the sump according to the present invention.

Fig. 11 is a schematic view of the anchor plate of the present invention.

Fig. 12 is a schematic view of the water drain pipe of the present invention.

Fig. 13 is a schematic view of the anchor plate and the clip of the present invention.

Fig. 14 is a schematic view of the wedge of the present invention.

The labels in the figures are: 1-side slope; 2-cement soil mixing pile; 3-section steel; 4-a crown beam; 41-wale; 5-inclined strut rigid beam; 51-a first diagonal rigid beam; 52-a second inclined strut rigid beam; 6, anchor cable; 61-a first anchor cable; 62-a second anchor cable; 63-a third anchor cable; 7-horizontal bracing rigid beam; 71-a first wale rigid beam; 72-a second cross brace rigid beam; 8-a ground drainage ditch; 9-anchoring means; 91-an anchorage device; 910-a clip; 92-channel steel; 93-anchor backing plate; 94-inclined sizing block; 95-a locking element; 101-a foundation pit drainage ditch; 102-a foundation pit water collecting well; 1021-bricking the side wall of the water collecting well; 1022-sump pit concrete floor; 11-bottom surface of deep foundation pit; 12-ground; 13-spraying a concrete layer; 131-a reinforcing mesh; 132-a downcomer; 133-a filter screen; 141-a first anchor cable anchoring section; 142-a second anchor cable anchoring section; 143-a third anchor cable anchoring section; 15-anchor plate; 16-bolt; 17-a stiffening steel plate; 18-dewatering well; 181-gravel filter layer; 182-washing the well pipe; 183-steel tube; 184-a water outlet pipe; 185-submersible pump; 19-reinforced concrete inclined cushion platform.

Detailed Description

The following description is made with reference to the accompanying drawings and examples, but not to be construed as limiting the invention.

As shown in fig. 1 to 14, a composite enclosure structure for a deep foundation pit comprises a water intercepting system, a supporting beam system for supporting the interior of the deep foundation pit and accelerating the construction progress, an anchor cable system and a drainage system for treating the seepage of the deep foundation pit; the water intercepting system divides the water intercepting work of the deep foundation pit into an overground part and an underground part, the overground part comprises a ground drainage ditch 8 which is preset at the periphery of the deep foundation pit before the deep foundation pit is dug, and the underground part encloses and forms the preset shape of the deep foundation pit; the supporting beam system comprises an upper structure and a lower structure which are arranged one by one in the process of excavating the deep foundation pit, the upper structure is used for enclosing the top of the deep foundation pit through a top beam 4, the upper structure is connected with the top of the underground part, the lower structure is arranged at the waist of the deep foundation pit and is used for enclosing the periphery of the deep foundation pit through a waist beam 41, and the area enclosed by the top beam 4 is larger than the area enclosed by the waist beam 41; the crown beam 4 and the waist beam 41 are supported and connected through the detachable inclined strut rigid beam 5 and the cross strut rigid beam 7; the drainage system comprises a foundation pit drainage ditch 101 dug and formed on the bottom surface 11 of the deep foundation pit, and the foundation pit drainage ditch 101 is arranged along the wall of the deep foundation pit.

As shown in fig. 2, the overground part also comprises a side slope 1, the side slope 1 is arranged between the ground drainage ditch 8 and the crown beam 4, and the side slope 1 and the ground drainage ditch 8 are spaced at a distance of 50cm; the side slope 1 is provided with a reinforcing mesh 131 and a sprayed concrete layer 13 in sequence from the ground to the outside, a drain pipe 132 is obliquely inserted into the side slope 1, the drain pipe 132 is arranged towards the direction of the deep foundation pit, and the filter mesh 133 is wrapped outside the drain pipe 132.

The ground drainage ditch 8 is located in the ground, two ends of the ground drainage ditch are flush with the ground, the ground drainage ditch 8 is of a brick masonry structure, side plates and a bottom plate of the brick masonry structure are 12cm thick, the net depth of the ground drainage ditch is 30cm, and the side faces and the bottom face are plastered by waterproof mortar with the thickness of 2 cm.

The slope ratio of the side slope 1 is 1, the reinforcing mesh 131 is arranged in two directions by reinforcing steel bars with the diameter of 6.5mm and the distance of 30cm, the lapping of reinforcing mesh sheets is not less than 40cm, and the reinforcing mesh sheets are fixed on the slope surface by U-shaped nails. The sprayed concrete layer 13 has a strength grade of C20 and a thickness of 6cm, and is divided into an inner sprayed concrete layer and an outer sprayed concrete layer, wherein the thickness of the inner sprayed concrete layer is not less than 3cm. The reinforcing mesh 131 is located between the inner sprayed concrete layer and the outer sprayed concrete layer, and serves to stabilize the slope together with the sprayed concrete layer 13.

As shown in fig. 12, the drain pipe 132 is a perforated PVC pipe with a diameter of 5cm, the aperture is 8mm, and the drain pipe 132 is arranged on the side slope 1 in a quincunx shape.

As shown in fig. 1-2, the underground part comprises a cement mixing pile 2 and section steel 3; a groove with the depth of 50cm is dug in advance before the cement soil mixing pile 2 is constructed, a working surface is provided for the construction of the cement soil mixing pile 2, the cement soil mixing pile 2 is positioned between the side slope 1 and the foundation pit, and a triaxial mixing pile structure is longitudinally formed; and the top beam 4 is connected with the top of the cement mixing pile 2 and the section steel 3; shaped steel 3 inserts and locates in the deep basal pit, and shaped steel 3 sets up in cement mixing pile 2, and the outstanding hat roof beam 4 in top of shaped steel 3. Shaped steel 3 adopts H shaped steel, and shaped steel 3's interval is 1.2m, and the adoption is inserted one and is jumped one the mode and insert soil cement mixing pile 2 in, plays stagnant water effect to the foundation ditch jointly through soil cement mixing pile 2 and shaped steel 3, and the 3 depths of insertion of shaped steel are 50cm apart from 2 bottoms of soil cement mixing pile, and 3 tops of shaped steel are higher than 2 tops of soil cement mixing pile 50cm.

The overground part and the underground part play a role in intercepting water together, ground rainwater and underground water are prevented from flowing into the foundation pit, a dry environment is provided for deep foundation pit excavation construction, and damages such as foundation pit instability and collapse caused by water seepage of the foundation pit are prevented.

As shown in fig. 2-6 and 11, the upper structure of the support system comprises a crown beam 4, a first inclined strut rigid beam 51 and a first cross strut rigid beam 71, the lower structure comprises a wale 41, a second inclined strut rigid beam 52 and a second cross strut rigid beam 72, and the crown beam 4 and the wale 41 are connected with the inclined strut rigid beam 5 and the cross strut rigid beam 7 through the mode of adding bolts 16 through an anchor plate 15; the top beam 4 is of a reinforced concrete structure, and the top beam 4 is positioned at the top of the cement mixing pile 2 and is adjacent to the foot of the side slope 1;

eight reinforced concrete inclined cushion platforms 19 are arranged at the edges of the crown beam 4 and the waist beam 41, and the reinforced concrete inclined cushion platforms 19 are poured together with the crown beam 4 and the waist beam 41; anchor plates 15 are pre-buried in the table top of the reinforced concrete inclined cushion platform 19, a first inclined strut rigid beam 51 is arranged between the reinforced concrete inclined cushion platforms 19 at the same corner, the anchor plates 15 are welded at the two end parts of the first inclined strut rigid beam 51, a stiffening steel plate 17 is vertically welded between the first inclined strut rigid beam 51 and the anchor plate 15 on the first inclined strut rigid beam, and the first inclined strut rigid beam 51 at the same corner and the reinforced concrete inclined cushion platform 19 are respectively connected on the anchor plate 15 through bolts 16; anchor plates 15 are respectively arranged at the two end parts of the first-path cross-brace rigid beam 71 and the contact side surface of the crown beam 4, a stiffening steel plate 17 is also arranged between the first-path cross-brace rigid beam 71 and the anchor plate 15 on the first-path cross-brace rigid beam, and the contact side surface of the first-path cross-brace rigid beam 71 and the crown beam 4 are respectively connected on the anchor plates 15 through bolts 16; the adjacent edges of the wale 41 are connected through a second inclined strut rigid beam 52, the connection mode and the structural mode of the second inclined strut rigid beam 52 are consistent with those of the first inclined strut rigid beam 51 on the crown beam 4, the opposite edges of the wale 41 are connected through a second cross strut rigid beam 72, and the connection mode and the structural mode of the second cross strut rigid beam 72 are consistent with those of the first cross strut rigid beam 71 on the crown beam 4.

The first inclined strut rigid beam 51 and the second inclined strut rigid beam 52 are made of prefabricated steel pipes,

as shown in fig. 1-2, the anchor cable system is distributed around the deep foundation pit, and the anchor cable system comprises anchor cables 6 and anchoring devices 9; the anchor cable 6 comprises a free section and an anchoring section, the free section of the anchor cable 6 is fixed through the anchoring device 9, the grouting material of the anchoring section of the anchor cable 6 adopts cement paste, and the anchor cable 6 is divided into a first part, a second part and a third part according to the construction penetration progress; the first section includes first anchor line 61 and first anchor line anchoring section 141, the second section includes second anchor line 62 and second anchor line anchoring section 142, and the third section includes third anchor line 63 and third anchor line anchoring section 143; the first anchor cable 61 is obliquely and downwards arranged on the crown beam 4, and forms an included angle of 30 degrees with the horizontal direction of the ground, and the anchoring section 141 of the first anchor cable is obliquely inserted into the soil body; the second anchor cable 62 is obliquely and downwards arranged between the crown beam 4 and the waist beam 41, the second anchor cable 62 is arranged on the pit wall of the deep foundation pit, an included angle of 30 degrees is formed between the second anchor cable 62 and the ground in the horizontal direction, and the anchoring section 142 of the second anchor cable is obliquely inserted into the soil body; the third anchor cable 63 is obliquely and downwardly arranged on the waist beam 41, and forms an included angle of 30 degrees with the horizontal direction of the ground, and the anchoring section 143 of the third anchor cable is obliquely inserted into the soil body; the lengths of the first anchor cable 61, the second anchor cable 62 and the third anchor cable 63 are shortened one by one; first cable 61, second cable 62 and third cable 63 are angled at the same angle.

The first anchor cable 61, the second anchor cable 62 and the third anchor cable 63 are all made of high-strength and low-relaxation steel strands.

As shown in fig. 2, 7, 13-14, the anchoring device 9 is disposed at the front end of the free section of the anchor cable 6, which does not extend into the soil, and the anchoring device 9 includes a locking element 95 disposed on the anchor cable 6, and an anchor 91, a channel 92, an anchor pad 93 and a wedge 94 which are separately disposed on the second anchor cable 62; the locking piece 95 is arranged on the free section of the anchor cable 6 and used for locking the tensioned free section of the anchor cable 6; the inclined sizing block 94 is arranged on the pit wall of the deep foundation pit, the inclined sizing block 94 is arranged to be close to the section steel 3, the inclined sizing block 94 is arranged in an inclined mode at the same angle with the second anchor cable 62, and holes are preset in the inclined sizing block 94 to provide stress surfaces for the anchor cables 6; the channel steel 92 is arranged on the inclined sizing block 94, the channel steel 92 is arranged in a left-right symmetrical mode, the channel steel 92 is transversely arranged, and a gap is reserved between the channel steel 92; the anchor backing plate 93 is arranged on the channel steel 92 and provides a stress surface for the anchor 91; the anchorage device 91 is arranged on the anchorage backing plate 93; through-pulling channels for anchor lines 6 are formed by the gaps between channel sections 92 and the holes in angled back iron 94. Four clamping pieces 910 connected with the anchor backing plate 93 are distributed around the anchor 91 in an annular shape around the through-pulling channel.

As shown in fig. 1-2, the drainage system is mainly used for drainage and precipitation in the excavation process of the deep foundation pit, so as to prevent hidden troubles such as collapse, piping and the like of the deep foundation pit due to the influence of underground water, and further comprises a foundation pit water collecting well 102; foundation ditch sump pit 102 locates the one corner of foundation ditch escape canal 101, and foundation ditch escape canal 101 is inside to set up certain slope, and domatic towards foundation ditch sump pit 102. As shown in fig. 10, the foundation pit collector 102 is composed of a collector concrete bottom plate 1022 and collector concrete side plates 1021.

Foundation ditch escape canal 101 is used for collecting the infiltration all around the foundation ditch, and foundation ditch escape canal 101 width is 30cm, and the degree of depth is 30cm, adopts the brick structure, and the thickness of brickwork is 12cm, and side and bottom surface are wiped by the waterproof mortar that thickness is 2 cm. The foundation pit water collecting well 102 is used for collecting collected water of the foundation pit drainage ditch 101, a concrete bottom plate 1022 of the water collecting well is of a concrete structure with the thickness of 15cm, a concrete side plate 1021 of the water collecting well is of a brick masonry structure with the thickness of 12cm, the net depth of the foundation pit water collecting well 102 is 80cm, and the side face of the foundation pit water collecting well is plastered by waterproof mortar with the thickness of 2 cm.

As shown in fig. 1-2, the drainage system further comprises a foundation pit dewatering well 18 which is continuously deep into the excavation process of the deep foundation pit, wherein the foundation pit dewatering well 18 is used for lowering the underground water level, providing a dry environment for foundation pit construction, and avoiding damages such as foundation pit collapse caused by the influence of underground water; the foundation pit dewatering wells 18 are arranged in the bottom surface 11 of the deep foundation pit, and the pair of foundation pit dewatering wells 18 are arranged in the deep foundation pit in a diagonal manner and extend into the soil body;

as shown in fig. 9-10, the foundation pit dewatering well 18 comprises a gravel filter layer 181, a well washing pipe 182, a steel pipe 183, a submersible pump 185 and a water outlet pipe 184; the gravel filter layer 181 is arranged on the outermost layer of the foundation pit dewatering well 18 in the soil body and is used for filtering larger-particle silt and providing a passage for groundwater seepage;

the steel pipe 183 is arranged on the inner side of the gravel filtering layer 181, the diameter of the steel pipe 183 is 15cm, holes are formed in the range of 5m below the steel pipe 183, the hole diameter is 15mm, the holes are arranged in a quincunx shape, the outer side of the steel pipe 183 is covered by a double-layer nylon net, the double-layer nylon net is used for filtering fine-particle silt, and conditions are provided for pumping water for the submersible pump 185 in the steel pipe 183;

the submersible pump 185 is arranged in the steel pipe 183, is close to the bottom of the steel pipe 183 and is used for pumping underground water out of the steel pipe 183;

the well washing pipe 182 is arranged in the gravel filter layer 181 and positioned outside the steel pipe 183, the insertion depth of the well washing pipe 182 is consistent with that of the submersible pump 185, and the well washing pipe 182 is a pipeline made of PVC and used for washing a well;

the water outlet pipe 184 is connected with the submersible pump 185, and the length of the water outlet pipe 184 is larger than that of the steel pipe 183, and is used for discharging the underground water in the foundation pit dewatering well 18.

Referring to fig. 1-14, based on the above, the present invention further provides a construction method of the deep foundation pit composite enclosure, which comprises the following steps:

s1: leveling the site of the pre-excavated deep foundation pit, performing measurement lofting on the deep foundation pit which is expected to be designed, and marking the position of the central axis of the pre-placed cement soil mixing pile 2 and the site of the trench excavation sideline;

s2: digging a groove, wherein the groove extends 50cm deep into the ground to provide a working surface for the construction of the cement-soil mixing pile 2;

s3: adopting a triaxial mixing pile machine to construct the cement mixing pile 2, wherein the mixing pile penetration depth is determined according to the soil quality condition;

s4: according to the setting time of the cement mixing pile 2, timely inserting the section steel 3 in a one-to-one inserting construction mode, brushing an antifriction material on the surface of the section steel 3 before inserting, wherein the insertion depth of the section steel 3 is 50cm away from the bottom of the cement mixing pile 2, and the top of the section steel 3 is required to be 50cm higher than the top of the cement mixing pile 2;

s5: the foundation pit dewatering well 18 is constructed firstly, the underground water level is continuously reduced by arranging the submersible pump 185, a dry environment is provided for deep foundation pit construction, and damages such as collapse of the deep foundation pit due to the influence of underground water are avoided;

s6: excavating the foundation pit and the side slope 1 for the first time, wherein the slope ratio of the side slope 1 is 1;

s7: hanging a reinforcing mesh 131 on the side slope 1, fixing the reinforcing mesh on the slope surface of the side slope 1 by using U-shaped nails, installing the drain pipe 132 in a quincunx arrangement, spraying a concrete layer 13 through layered construction, and maintaining;

s8: excavating and building a ground drainage ditch 8 at the periphery of the side slope 1;

s9: drilling holes in the pre-buried direction of the first anchor cable 61, placing the first anchor cable 61, grouting around the first anchor cable anchoring section 141 according to the holes, and maintaining;

s10: binding the steel bars of the crown beam 4, and embedding and installing the anchor plate 15 on the reinforced concrete inclined pad platform 19 at the same time, so as to carry out the installation of the anchor plate 15 and the construction and maintenance of concrete pouring of the crown beam 4 and the reinforced concrete inclined pad platform 19;

s11: connecting the first cross brace rigid beam 71 and the reinforced concrete inclined pad platform 19 through the anchor plate 15 by using the bolt 16, and directly connecting the first cross brace rigid beam 51 and the crown beam 4 through the anchor plate 15 by using the bolt 16 so as to provide support for the foundation pit through the crown beam 4;

s12: the free section of the first anchor line 61 is anchored and mounted through a locking piece 95 and is locked and mounted on the crown beam 4;

s13: excavating the foundation pit for the second time, wherein the preset depth of the bottom of the foundation pit excavated for the second time is flush with the elevation of the second anchor cable 62;

s14: drilling holes in the pre-buried direction of the second anchor cable 62, placing the second anchor cable 62, grouting around the anchoring section 142 of the second anchor cable and maintaining;

s15: installing the free section of a second anchor cable 62 through a through-pulling channel formed in the anchoring device 9, and locking and clinging to the section steel 3 through the cement-soil mixing pile 2;

s16: excavating the foundation pit for the third time, wherein the estimated depth of the bottom 11 of the foundation pit excavated for the third time is flush with the elevation of the bottom of the waist beam 41;

s17: drilling holes in the pre-buried direction of the third anchor cable 63, placing the third anchor cable 63, grouting around the anchoring section 143 of the third anchor cable, and maintaining;

s18: binding steel bars on the wale 41, and simultaneously installing the anchor plate 15 on the reinforced concrete inclined pad platform 19 in a pre-embedded manner, so as to install the anchor plate 15, and constructing and maintaining concrete pouring of the wale 41 and the reinforced concrete inclined pad platform 19;

s19: connecting the second inclined strut rigid beam 52 with the reinforced concrete inclined pad platform 19 through the anchor plate 15 by using bolts 16, and directly connecting the second transverse strut rigid beam 72 with the waist beam 41 through the anchor plate 15 by using the bolts 16 so as to provide support for the foundation pit through the waist beam 41;

s20: the free section of the third anchor cable 63 is anchored and installed through a locking piece 95 and is locked and installed on the wale 41;

s21: excavating the foundation pit for the fourth time, wherein the bottom depth of the foundation pit excavated for the fourth time is flush with the elevation of the bottom surface 11 of the designed deep foundation pit, so that the excavation of the deep foundation pit is completed;

s22: a foundation pit drainage ditch 101 and a foundation pit water collecting well 102 are excavated and built on the bottom surface 11 of the deep foundation pit, so that hidden dangers such as collapse and piping caused by underground water in the deep foundation pit are prevented.

The above embodiments are merely preferred technical solutions of the present invention, and it should be understood by those skilled in the art that modifications or substitutions of technical solutions or parameters in the embodiments can be made without departing from the principles and essential conditions of the present invention, and all the modifications or substitutions should be covered within the protection scope of the present invention.

Claims (8)

1. The utility model provides a compound envelope of deep basal pit which characterized in that: the system comprises a water interception system, a supporting beam system, an anchor cable system and a drainage system, wherein the supporting beam system supports the interior of the deep foundation pit and can accelerate the construction progress;

the water intercepting system divides the water intercepting work of the deep foundation pit into an overground part and an underground part, the overground part comprises ground drainage ditches (8) which are preset on the periphery of the deep foundation pit before the deep foundation pit is excavated, and the underground part forms a preset shape of the deep foundation pit in a surrounding way;

the supporting beam system comprises an upper structure and a lower structure which are arranged one by one in the process of excavating the deep foundation pit, the upper structure is used for enclosing the top of the deep foundation pit through a crown beam (4), the upper structure is connected with the top of the underground part, and the lower structure is arranged at the waist of the deep foundation pit and is used for enclosing the periphery of the deep foundation pit through a waist beam (41); the crown beam (4) and the waist beam (41) are supported and connected through a detachable inclined strut rigid beam (5) and a cross strut rigid beam (7);

the drainage system comprises a foundation pit drainage ditch (101) dug and formed on the bottom surface (11) of the deep foundation pit, and the foundation pit drainage ditch (101) is arranged along the wall of the deep foundation pit.

2. The deep foundation pit composite enclosure structure of claim 1, wherein: the overground part also comprises a side slope (1), the side slope (1) is arranged between the ground drainage ditch (8) and the crown beam (4), and an interval is formed between the side slope (1) and the ground drainage ditch (8);

slope (1) sets gradually reinforcing bar net (131) and sprayed concrete layer (13) outwards by ground, slope (1) is gone into to one side and is provided with outlet pipe (132) of inserting, just outlet pipe (132) orientation deep basal pit direction sets up, outlet pipe (132) are wrapped up in outward and have filter screen (133).

3. The deep foundation pit composite enclosure structure of claim 1, wherein: the underground part comprises a cement soil mixing pile (2) and section steel (3);

the cement-soil mixing piles (2) are arranged around the deep foundation pit, and the crown beams (4) are connected with the tops of the cement-soil mixing piles (2) and the section steel (3);

the section steel (3) is inserted into the deep foundation pit, the section steel (3) is arranged in the cement-soil mixing pile (2), and the top of the section steel (3) protrudes out of the crown beam (4).

4. The deep foundation pit composite building envelope of claim 1, characterized in that: the crown beam (4) and the waist beam (41) are connected with the inclined strut rigid beam (5) and the cross strut rigid beam (7) in a mode of adding bolts (16) to an anchor plate (15);

both ends of one side of the crown beam (4) and the waist beam (41) are provided with reinforced concrete inclined cushion platforms (19); the anchor plates (15) are pre-buried in the table top of the reinforced concrete inclined cushion table (19), a first inclined strut rigid beam (51) is arranged between the reinforced concrete inclined cushion tables (19) at the same corner, the anchor plates (15) are arranged at two end parts of the first inclined strut rigid beam (51), a stiffening steel plate (17) is arranged between the first inclined strut rigid beam (51) and the anchor plate (15) on the first inclined strut rigid beam, and the first inclined strut rigid beam (51) at the same corner and the reinforced concrete inclined cushion tables (19) are respectively connected on the anchor plates (15) through the bolts (16); the anchor plates (15) are respectively arranged at two end parts of the first cross-brace rigid beam (71) and the contact side surface of the crown beam (4), the stiffening steel plate (17) is also arranged between the first cross-brace rigid beam (71) and the anchor plate (15) on the first cross-brace rigid beam, and the contact side surfaces of the first cross-brace rigid beam (71) and the crown beam (4) are respectively connected on the anchor plates (15) through the bolts (16);

the adjacent limit of waist rail (41) is connected through second bracing stiffening beam (52), just the connected mode of second bracing stiffening beam (52) with crown beam (4) is gone up the connected mode of first bracing stiffening beam (51) is unanimous, the relative limit of waist rail (41) is connected through second bracing stiffening beam (72), just the connected mode of second bracing stiffening beam (72) with crown beam (4) is last the connected mode of first bracing stiffening beam (71) is unanimous.

5. The deep foundation pit composite enclosure structure of claim 1, wherein: the anchor cable system is distributed around the deep foundation pit and comprises anchor cables (6) and anchoring devices (9); the anchor cable (6) is divided into a first part, a second part and a third part according to the construction penetration progress; the first portion comprising a first cable bolt (61) and a first cable bolt anchoring segment (141), the second portion comprising a second cable bolt (62) and a second cable bolt anchoring segment (142), the third portion comprising a third cable bolt (63) and a third cable bolt anchoring segment (143);

the first anchor cable (61) is obliquely and downwards arranged on the crown beam (4), and the anchoring section (141) of the first anchor cable is obliquely inserted into the soil body;

the second anchor cable (62) is obliquely and downwards arranged between the crown beam (4) and the waist beam (41), the second anchor cable (62) is arranged on the wall of the deep foundation pit, and the anchoring section (142) of the second anchor cable is obliquely inserted into the soil body;

the third anchor cable (63) is obliquely and downwards arranged on the waist beam (41), and the anchoring section (143) of the third anchor cable is obliquely inserted into the soil body;

the lengths of the first anchor cable (61), the second anchor cable (62) and the third anchor cable (63) are shortened one by one.

6. The deep foundation pit composite enclosure structure of claim 5, wherein: the anchoring device (9) comprises a locking piece (95) arranged on the anchor cable (6), and an anchorage device (91), a channel steel (92), an anchorage plate (93) and an inclined pad iron (94) which are separately arranged on the second anchor cable (62);

the locking piece (95) is arranged on the free section of the anchor cable (6) and used for locking the tensioned anchor cable (6);

the inclined sizing block (94) is arranged on the wall of the deep foundation pit, the inclined sizing block (94) is arranged in an inclined mode at the same angle with the second anchor cable (62), and a hole is preset in the inclined sizing block (94);

the channel steel (92) is arranged on the inclined sizing block (94), and a gap is reserved between the channel steel (92);

the anchor backing plate (93) is arranged on the channel steel (92);

the anchorage device (91) is arranged on the anchorage backing plate (93);

and a penetrating and pulling channel of the anchor cable (6) is formed by the gap between the channel steels (92) and the hole in the inclined sizing block (94).

7. The deep foundation pit composite building envelope of claim 1, characterized in that: the drainage system further comprises a foundation pit water collection well (102); foundation ditch sump pit (102) are located foundation ditch escape canal (101), foundation ditch escape canal (101) are inside to set up the grade, and domatic orientation foundation ditch sump pit (102).

8. The deep foundation pit composite enclosure structure of claim 1, wherein: the drainage system also comprises a foundation pit dewatering well (18) which is continuously deep in the deep foundation pit excavation process; the foundation pit dewatering well (18) is arranged in the bottom surface (11) of the deep foundation pit, and the foundation pit dewatering well (18) comprises a gravel filter layer (181), a well washing pipe (182), a steel pipe (183), a submersible pump (185) and a water outlet pipe (184);

the gravel filter layer (181) is arranged on the outermost layer of the foundation pit dewatering well (18) in the soil body;

the steel pipe (183) is arranged on the inner side of the gravel filter layer (181);

the submersible pump (185) is arranged in the steel pipe (183);

the well washing pipe (182) is arranged in the gravel filter layer (181) and positioned outside the steel pipe (183), and the insertion depth of the well washing pipe (182) is consistent with the depth of the submersible pump (185);

the water outlet pipe (184) is connected with the submersible pump (185), and the length of the water outlet pipe (184) is larger than that of the steel pipe (183).

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