CN104018475A - Embedded type penstock backfill grouting structure and grouting technology - Google Patents

Embedded type penstock backfill grouting structure and grouting technology Download PDF

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Publication number
CN104018475A
CN104018475A CN201410211084.3A CN201410211084A CN104018475A CN 104018475 A CN104018475 A CN 104018475A CN 201410211084 A CN201410211084 A CN 201410211084A CN 104018475 A CN104018475 A CN 104018475A
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grouting
penstock
backfill
embedded
concrete
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CN201410211084.3A
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CN104018475B (en
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湛正刚
申显柱
罗玉霞
李晓彬
孙卫
杜帅群
任兴普
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PowerChina Guiyang Engineering Corp Ltd
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Hydrochina Guiyang Engineering Corp
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/20Hydro energy

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Abstract

The invention discloses an embedded type penstock backfill grouting structure and a grouting technology. The grouting structure comprises a penstock and a water draining opening formed in the outside the penstock, wherein a plurality of longitudinal grouting pipes and a plurality of transverse grouting pipes are embedded in the outer side of the penstock through backfill concrete, pneumatically placed concrete is arranged on the outer surface of the backfill concrete, the water draining opening is provided with rock holes in which grouting pipes are embedded, and the grouting pipes are communicated with the longitudinal grouting pipes and the transverse grouting pipes. The grouting technology comprises the steps of drilling, pipe embedding, grouting, grouting completing, hole sealing and quality checking. The grouting structure is arranged in cooperation with the water draining opening, the grouting pipes embedded in the rock holes are communicated with the grouting pipes embedded outside the penstock, grouting is performed by adopting the pushing grouting method, so that the penstock and surrounding rock bear force in a linkage mode, it is guaranteed that pressure of internal water is transmitted fully, whole stress of the penstock, the concrete and the surrounding rock is guaranteed, and the problem of the void between the backfill concrete and the surrounding rock is solved.

Description

A kind of embedded penstock backfill grouting structure and grouting process thereof
Technical field
The present invention relates to a kind of embedded penstock backfill grouting structure and grouting process thereof, belong to water conservancy and hydropower technical field.
Background technology
Hydropower station pressure pipeline refers to pipeline from surge-chamber to the power plant building hydraulic turbine that carry the water yield from reservoir, forebay or, and wherein embedded penstock refers to and imbeds the concrete steel pipe of filling in rock mass and between steel pipe and country rock.According to construction of hydropower plant development, most of engineerings because Penstock Structures is arranged, uneven, the concrete shrinkage of excavation face or the factor such as construction technology is improper, cause the gradient to be delayed and between the penstock fill concrete lining ring crown of 45 ° and country rock, have large " coming to nothing ", while affecting the safety of steel pipe operation, tackle the position of coming to nothing and carry out backfill grouting.At present, backfill grouting processing mode mainly contains at steel pipe crown preformed hole or along two kinds of crag pre-embedment grouting pipes, the potential safety hazard that preformed hole mode the number of openings is many, blindness is large, aperture is greater than 50mm conventionally, weld reinforcement technological requirement is high and solder skip exists interior water to exosmose, built-in pipe mode was easily blocked and affects later stage grouting effect in construction period, and long construction period, complex process, blindness are large, construction investment, security reliability is poor.How therefore a kind of short construction period be provided, and safe and reliable embedded penstock backfill grouting structure, is current hydropower station pressure pipeline technical field of construction problem demanding prompt solution.
Summary of the invention
For addressing the above problem, the invention provides a kind of embedded penstock backfill grouting structure and grouting process thereof, thereby reach the object of effective raising backfill grouting construction effect.
The present invention is achieved by following technical solution.
A kind of embedded penstock backfill grouting structure and grouting process thereof, comprise penstock and the drainage tunnel that is arranged at penstock outside, described penstock outside is embedded with some longitudinal grout pipes and horizontal grout pipe by fill concrete, be provided with pneumatically placed concrete at fill concrete external surface, on described drainage tunnel, be provided with petrosal foramen, in petrosal foramen, be embedded with grout pipe, described grout pipe is communicated with longitudinal grout pipe and horizontal grout pipe respectively.
The diameter of described petrosal foramen is 75mm.
Described longitudinal grout pipe top is provided with some longitudinal grouting mouthful.
Described horizontal grout pipe top is provided with some horizontal grouting mouthful.
The diameter of described longitudinal grouting mouth is 30mm, pitch-row 1000mm.
The diameter of described longitudinal grouting mouth is 30mm, pitch-row 300mm.
Described grout pipe adopts φ 50mm polyethylene hard tube, and is fixed on pneumatically placed concrete by the cement nail with pad.
Described grout pipe arranged outside has stop grouting plug.
The present invention also provides a kind of embedded penstock backfill grouting technique, mainly comprises following processing step:
(1) boring: before concrete backfill, from the drainage tunnel at penstock top, bore φ 75mm petrosal foramen, and in petrosal foramen pre-buried φ 50mm polyethylene hard tube grout pipe;
(2) pipe laying: at penstock 120 ° of pre-buried longitudinal grout pipes of outside crown and horizontal grout pipe, grout pipe adopts φ 50mm polyethylene hard tube, and adopts the cement nail with pad that grout pipe is fixed on pneumatically placed concrete before concrete backfill;
(3) grouting: reach after 70% design strength at the lining concrete of respective regions, carry out backfill grouting, crown backfill grouting adopts a point section to carry out, each standard paragraphs pipe range 12m that is longitudinally in the milk, non-standard segment length determines by a construction section; Closely knit with mortar or concrete shutoff in sectional end, to form isolated area, grouting construction, from lower one end, advances by ring to higher one end;
(4) grouting finishes and sealing of hole: in the time that inlet pipe grout absorption is equal with slurry-outlet quantity, continuity perfusion 10min, can finish; After grout hole grouting and inspection eye inspection finish, answer evacuation aperture internal water accumulation and dirt, adopt the dry cement mortar packing of holing closely knit, aperture pressure is smeared and is flushed;
(5) quality examination: the boring of inspection eye is carried out from the drainage tunnel at penstock top.
To adopt water/binder ratio be 0.6 or the cement paste of 0.5:1 in grouting in above-mentioned steps (3), grouting pressure 0.2~0.3Mpa.
The invention has the beneficial effects as follows:
Compared with prior art, the present invention arranges in conjunction with drainage tunnel, be interconnected by pre-embedment grouting pipe in petrosal foramen and the outside pre-embedment grouting pipe of penstock, and adopt to push away to catch up with grouting technique to be in the milk to start from lower one end to higher one end and advance by ring, make penstock and country rock coaction; Backfill grouting forms calculus by grout injection (or cement mortar), in order to coming to nothing between filling fill concrete lining ring crown and country rock, ensure the abundant transmission of internal water pressure, not only keep the integrality of steel pipe, ensure that steel pipe, concrete and country rock entirety are stressed, and solved the problem of coming to nothing between fill concrete and country rock, increase the safety of steel pipe operation; The present invention is simple for structure, effectively improves backfill grouting construction effect, and reduction of erection time and cost saving greatly, has good economic benefit and social benefit.
Brief description of the drawings
Fig. 1 is embedded penstock grouting vertical section structure schematic diagram of the present invention;
Fig. 2 is the A place structure enlarged diagram of Fig. 1;
Fig. 3 is the B-B sectional drawing of Fig. 1;
Fig. 4 is the C place structure enlarged diagram of Fig. 3.
In figure: 1-penstock, 2-drainage tunnel, 3-petrosal foramen, the longitudinal grout pipe of 4-, the horizontal grout pipe of 5-, 6-fill concrete, 7-pneumatically placed concrete, 8-stop grouting plug, 9-grout compartment line of demarcation, 31-grout pipe, the 41-mouth that is longitudinally in the milk, the 51-mouth that is laterally in the milk.
Detailed description of the invention
Further describe technical scheme of the present invention below in conjunction with accompanying drawing, but described in claimed scope is not limited to.
As shown in Figures 1 to 4, the embedded penstock backfill grouting of one of the present invention structure, comprise penstock 1 and the drainage tunnel 2 that is arranged at penstock 1 outside, described penstock 1 outside is embedded with some longitudinal grout pipes 4 and horizontal grout pipe 5 by fill concrete 6, be provided with pneumatically placed concrete 7 at fill concrete 6 external surfaces, on described drainage tunnel 2, be provided with petrosal foramen 3, in petrosal foramen 3, be embedded with grout pipe 31, described grout pipe 31 is communicated with longitudinal grout pipe 4 and horizontal grout pipe 5 respectively.
The diameter of described petrosal foramen 3 is 75mm.
Described longitudinal grout pipe 4 tops are provided with some longitudinal grouting mouths 41.
Described horizontal grout pipe 5 tops are provided with some horizontal grouting mouths 51.
The diameter of described longitudinal grouting mouth 41 is 30mm, pitch-row 1000mm.
The diameter of described longitudinal grouting mouth 51 is 30mm, pitch-row 300mm.
Described grout pipe 31 adopts φ 50mm polyethylene hard tube, and by being fixed on pneumatically placed concrete 7 or on country rock wall with the cement nail of pad.
Described grout pipe 31 arranged outside have stop grouting plug 8.Can overcome so the excessive risk of grouting slurries.
Adopt technique scheme in the time of construction, form and connect loop by φ 75mm petrosal foramen 3 and pre-embedment grouting pipe; Grouting construction can adopt to push away catches up with grouting, i.e. construction, from lower one end, advances by ring to higher one end.Backfill grouting is to form calculus by grout injection (or cement mortar), in order to coming to nothing between filling fill concrete 6 lining ring crowns and country rock, meet steel pipe and country rock coaction, ensure the abundant transmission of internal water pressure, this point is very important for the embedded penstock of considering surrounding rock to share internal water pressure.Adopt this technical scheme not only to keep the integrality of steel pipe, ensured the stressed feature of steel pipe, concrete and country rock entirety, and solved the problem of coming to nothing between fill concrete 6 and country rock, increase the safety of steel pipe operation.
Embodiments of the invention: when penstock 1 because structural configuration, excavation face are uneven, concrete shrinkage or the factor such as construction technology is improper, cause the gradient to be delayed between the penstock fill concrete lining ring crown of 45 ° and country rock and occur " harmful coming to nothing " phenomenon, while affecting the safety of steel pipe operation, should carry out backfill grouting to the position of coming to nothing by structure of the present invention, its concrete backfill grouting implementation step is as follows:
(1) boring: according to bore φ 75mm petrosal foramen 3 shown in Fig. 1 to Fig. 4 from the drainage tunnel 2 at penstock 1 top, and guaranteed not get into penstock 1 before concrete backfill; And in petrosal foramen 3 pre-buried φ 50mm polyethylene hard tube grout pipe 31;
(2) pipe laying: before concrete backfill at the pre-buried longitudinal grout pipes 4 of 120 ° of outside crowns of penstock 1 and horizontal grout pipe 5, grout pipe adopts φ 50mm polyethylene hard tube, and adopts the cement nail with pad that grout pipe is fixed on pneumatically placed concrete 7 or on country rock wall.Longitudinal grouting mouth 41 of φ 30mm is set, pitch-row 1000mm at longitudinal grout pipe 4 tops; The horizontal grouting mouthful of φ 30mm is set, pitch-row 300mm at horizontal grout pipe 5 tops.Built-in pipe connect after should carry out stressed inspection and fill, return-air inspection, the pipeline of guaranteeing to be in the milk connect; In the time of fill concrete, tackle backfill grouting pipe and protected, in order to avoid stop up aperture.
(3) grouting: backfill grouting must reach after 70% design strength at the lining concrete of respective regions, can carry out.Crown backfill grouting should be carried out according to grout compartment line of demarcation 9 subregions as shown in Figure 1, each standard paragraphs pipe range 12m that is longitudinally in the milk, and non-standard segment length determines by a construction section; As shown in Figure 2, the end of grout compartment line of demarcation 9 place's sections is closely knit with mortar or concrete shutoff, to form isolated area; Grouting process adopts " push away and catch up with grouting ", i.e. construction, from lower one end, advances by ring to higher one end, and a in Fig. 1, Fig. 2 represents that, into slurry direction, b represents pulp direction; Priming petock gray scale is 0.6 (or 0.5): 1 cement paste, between lining ring crown and country rock, exist the position in larger space to answer the cement mortar that priming petock gray scale is lower, grouting pressure 0.2~0.3Mpa, can adjust according to grouting actual conditions, and pressure should ascendingly increase step by step; In filling process, should splash the distortion of steel pipe, prevent steel pipe tube wall unstability;
(4) grouting ending standard and method for sealing: under the pressure of design code, in the time that inlet pipe grout absorption is equal with slurry-outlet quantity, continuity perfusion 10min, can finish; After grout hole grouting and inspection eye inspection finish, answer evacuation aperture internal water accumulation and dirt, adopt " full hole grouting method of pore sealing " closely knit with the dry cement mortar packing of holing, aperture pressure is smeared and is flushed;
(5) quality examination: the boring of inspection eye is carried out from the drainage tunnel at penstock top, and prevent from getting into penstock.

Claims (10)

1. an embedded penstock backfill grouting structure, comprise penstock (1) and be arranged at the outside drainage tunnel (2) of penstock (1), it is characterized in that: described penstock (1) outside is embedded with some longitudinal grout pipes (4) and horizontal grout pipe (5) by fill concrete (6), be provided with pneumatically placed concrete (7) at fill concrete (6) external surface, on described drainage tunnel (2), be provided with petrosal foramen (3), in petrosal foramen (3), be embedded with grout pipe (31), described grout pipe (31) is communicated with longitudinal grout pipe (4) and horizontal grout pipe (5) respectively.
2. the embedded penstock backfill grouting of one according to claim 1 structure, is characterized in that: the diameter of described petrosal foramen (3) is 75mm.
3. the embedded penstock backfill grouting of one according to claim 1 structure, is characterized in that: described longitudinal grout pipe (4) top is provided with some longitudinal grouting mouthful (41).
4. the embedded penstock backfill grouting of one according to claim 1 structure, is characterized in that: described horizontal grout pipe (5) top is provided with some horizontal grouting mouthful (51).
5. the embedded penstock backfill grouting of one according to claim 3 structure, is characterized in that: the diameter of described longitudinal grouting mouthful (41) is 30mm, pitch-row 1000mm.
6. the embedded penstock backfill grouting of one according to claim 4 structure, is characterized in that: the diameter of described longitudinal grouting mouthful (51) is 30mm, pitch-row 300mm.
7. the embedded penstock backfill grouting of one according to claim 1 structure, is characterized in that: described grout pipe (31) adopts φ 50mm polyethylene hard tube, and by being fixed on pneumatically placed concrete (7) with the cement nail of pad.
8. the embedded penstock backfill grouting of one according to claim 1 structure, is characterized in that: described grout pipe (31) arranged outside has stop grouting plug (8).
9. an embedded penstock backfill grouting technique, is characterized in that: mainly comprise following processing step:
(1) boring: before concrete backfill from the drainage tunnel (2) at penstock (1) top brill φ 75mm petrosal foramen (3), and in petrosal foramen (3) pre-buried φ 50mm polyethylene hard tube grout pipe (31);
(2) pipe laying: before concrete backfill at penstock (1) 120 ° of pre-buried longitudinal grout pipes of outside crown (4) and horizontal grout pipe (5), grout pipe adopts φ 50mm polyethylene hard tube, and adopts the cement nail with pad that grout pipe is fixed on pneumatically placed concrete (7);
(3) grouting: reach after 70% design strength at the lining concrete of respective regions, carry out backfill grouting, crown backfill grouting adopts a point section to carry out, each standard paragraphs pipe range 12m that is longitudinally in the milk, non-standard segment length determines by a construction section; Closely knit with mortar or concrete shutoff in sectional end, to form isolated area, grouting construction, from lower one end, advances by ring to higher one end;
(4) grouting finishes and sealing of hole: in the time that inlet pipe grout absorption is equal with slurry-outlet quantity, continuity perfusion 10min, can finish; After grout hole grouting and inspection eye inspection finish, answer evacuation aperture internal water accumulation and dirt, adopt the dry cement mortar packing of holing closely knit, aperture pressure is smeared and is flushed;
(5) quality examination: the boring of inspection eye is carried out from the drainage tunnel at penstock top.
10. the embedded penstock backfill grouting of one according to claim 9 technique, is characterized in that: to adopt water/binder ratio be 0.6 or the cement paste of 0.5:1 in grouting in described step (3), grouting pressure 0.2~0.3Mpa.
CN201410211084.3A 2014-05-19 2014-05-19 A kind of embedded penstock backfill grouting structure and grouting process thereof Active CN104018475B (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104832707A (en) * 2015-04-14 2015-08-12 成都聚智工业设计有限公司 Pressure steel pipe embedded structure
CN107255705A (en) * 2017-07-24 2017-10-17 河海大学 Microorganism grouting test device and test method for uniform curing silt

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10122432A (en) * 1996-08-28 1998-05-15 Osaka Gas Co Ltd Replacing method and drawing method for underground embedded pipe
CN101418557A (en) * 2008-10-15 2009-04-29 中国水利水电第五工程局有限公司 Horizontal backfill grouting construction process of pressure conduit for hydraulic power plant
CN203188218U (en) * 2013-04-03 2013-09-11 福建岩土工程勘察研究院 Grouting device
CN203890980U (en) * 2014-05-19 2014-10-22 中国水电顾问集团贵阳勘测设计研究院有限公司 Backfilling and grouting structure for buried pressure pipe

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10122432A (en) * 1996-08-28 1998-05-15 Osaka Gas Co Ltd Replacing method and drawing method for underground embedded pipe
CN101418557A (en) * 2008-10-15 2009-04-29 中国水利水电第五工程局有限公司 Horizontal backfill grouting construction process of pressure conduit for hydraulic power plant
CN203188218U (en) * 2013-04-03 2013-09-11 福建岩土工程勘察研究院 Grouting device
CN203890980U (en) * 2014-05-19 2014-10-22 中国水电顾问集团贵阳勘测设计研究院有限公司 Backfilling and grouting structure for buried pressure pipe

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
文清柏: "润海水电站引水隧洞压力钢管管底", 《湖南水利水电》, no. 2, 30 April 2007 (2007-04-30) *
李昌林: "输水隧洞PCCP管安装与回填灌浆工艺", 《广东水利水电》, no. 9, 30 September 2010 (2010-09-30), pages 45 - 47 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104832707A (en) * 2015-04-14 2015-08-12 成都聚智工业设计有限公司 Pressure steel pipe embedded structure
CN107255705A (en) * 2017-07-24 2017-10-17 河海大学 Microorganism grouting test device and test method for uniform curing silt
CN107255705B (en) * 2017-07-24 2023-07-21 河海大学 Microbial grouting test device and method for uniformly curing silt

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Address after: 550000 No. 16 Xingqian Road, Guanshan Lake District, Guiyang City, Guizhou Province

Patentee after: POWERCHINA GUIYANG ENGINEERING CORPORATION LIMITED

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Address before: 550081 Zhongshui Guiyang Courtyard, No. 16 Xingqian Road, Guanshan Lake District, Guiyang City, Guizhou Province

Patentee before: POWERCHINA GUIYANG ENGINEERING Corp.,Ltd.

Country or region before: China