Seashore and man-made island underground structure construction method
The present invention relates to technical fields such as port works, construction work, highway engineering, underground construction, be specifically related to the building technology of seashore reclaiming land around sea district harbour underground structure, man-made island underground structure and bridge tunnel transformational structure.
Along with China's rapid economy development, traffic infrastructure such as water transport, highway building size is unprecedented in recent years, comprises infrastructure projects such as port and pier, man-made island airport, (river) over strait tunnel.
Shipping (container, bulk goods etc.) harbour generally is built on the land-based area that encloses sea formation; The reclaiming land around sea area should be confirmed according to newly-built harbour design scale; And along with economic development; The shipping handling capacity that the pier storage yard area has seriously restricted harbour promotes; For this reason, need harbour is remodeled and expand raising shipping handling capacity.Because of ocean monsoon climate (particularly typhoon) influence, the goods preloading of harbour rear is unsuitable too high, causes the stockyard area occupied big, and the large tracts of land reclaiming land around sea makes construction costs high, long in time limit.For enlarging the cargo berth scale; Promote handling capacity, the goods yard area needs corresponding increase, takies more reclaiming land around sea area; So that the big contradiction with coastal area backfill resource scarcity of backfill demand occurs, the continuous reclaiming land around sea of while along the coastline also causes adverse effect to marine environment.Ancillary facilities such as the control room that passenger wharf is built, passenger's waiting room, warehouse, garage are influenced by oceanic winds, and terminal facilities designs low-rise building usually, and floor space is big, like harbours such as Tianjin, Wenzhou, Lianyun Harbour, Xiamen, Nansha, Guangzhou, Shenzhen She Kou.The Wharf Construction initial stage plans that with regard to underground space development utilization then the later stage transforms or builds and will save construction costs.
The city is the sign of modern civilization and social progress, is the main carrier of economy and social development.Be accompanied by the quickening in China city, urban construction is fast-developing, and city size constantly enlarges; Urban population sharply expands, and it is nervous that building land has appearred in many cities to some extent, and living space is crowded; Traffic jam; Infrastructure falls behind, disruption of ecological balance, problems such as ecological deterioration; Be referred to as "urban disease"; Bring very big influence for the human living condition, also restricted economic with social further developing, become the obstacle of modern city sustainable development.Traffic congestion, road speed have slowly become the general very distinct issues in the many cities of China; The development of underground traffic (underground space) and viaduct (upper space) makes problem be eased to a certain extent, but the development that the planning difficulty of viaduct traffic is big, noise disturbs residents, overpass bridge restriction etc. has restricted viaduct; Along with technical development, also can carry out the exploitation of the underground space in the existing building bottom and build, be beneficial to planning, and noise there is not influence to ground, make underground traffics such as tunnel, subway with the obvious advantage.Perfect infrastructure device is to improve the necessary condition of urban environment.Urban development be unable to do without infrastructure such as power supply, water supply, communication, heat supply, solid refuse stacking.The city of current developed country utilizes the important channel as the critical facility that solves urban population, environment, resource three big crises and treatment " city integrated disease ", enforcement sustainable development to underground space development.Along with economy development of coastal area, the seabeach of today and passenger wharf periphery form tourism and business circles gradually, become the bustling city of tomorrow, and soil anxiety, traffic congestion, repeated construction become the obstacle of its development equally.
Along with marine development of resources and bridge spanning the sea construction, a large amount of marine man-made islands are built to, like bridge tunnel conversion man-made island, airport, deep water port, oil platform, port man-made island, and the man-made island of tourism development.Along with building up of Japan blue or green letter tunnel, Great Britain and France's seabed tunnel; The tunnel is warm at the bottom of causing a seabed and river in the world wide; China has also proposed Qiongzhou Strait seabed tunnel and the construction plan of striding the tunnel, Bohai Sea Gulf, and the ventilation opening of overlength seabed tunnel setting need be built on the man-made island; Bridge spanning the sea adopts bridge and tunnel combining form more, needs to build marine man-made island so that marine bridge is connected with seabed tunnel, and tunnel excavation of foundation pit mode is adopted in the bridge tunnel conversion on the man-made island.
Port and pier stockyard and ancillary facility construction scheme at present is to enclose the sea earlier to form land-based area, and redevelopment is built after the payment Construction unit.Enclose the sea by place absolute altitude requirement and form land-based area, then planning construction is carried out in the place, comprise stockyard, office building, time guest room and relevant ancillary facility, very lack its underground space development is utilized.Urban underground space construction method: adopt open-cut foundation ditch to build the form of construction work of underground structure, or adopt the form of construction work of non-open cuts such as tunneling, shield driving, push pipe.Carry out the underground space development construction at harbour or man-made island, one of traditional construction method is to enclose the sea earlier to form land-based area, refers again to the urban underground space construction method; It two is directly heavyly in water to put precast construction, bury pipeline etc. underground, carries out peripheral backfill again.
To man-made island and seashore underground space tradition construction method one: in the waters, fill earlier the cofferdam; Treat that the cofferdam forms backfill epeirogenetic such as back hydraulic fill sand or mud; After carry out reinforcing soft foundation; On artificial land-based area (island), carry out the space enclosing structure construction; Carry out underground excavation of foundation pit in succession, finally in the foundation ditch of excavation, carry out the underground structure construction.It is big that this construction method is filled out extra large backfill amount, and coastal resources (particularly sand, native stone cuts into a mountain) in short supply causes that construction duration is long, construction costs is high; The working procedure that has adopted first backfill to excavate again, construction sequence repeat, and cause that engineering quantity is huge, efficiency of construction is low.
If adopt in the water precast construction and bury pipeline underground, can save the operation of excavation of foundation pit and supporting, save cost, but construction quality is difficult for assurance with safety, the waterproof of its underground space structure and anticorrosion are difficult to meet the demands.
Therefore, propose that a kind of efficiency of construction is high, the duration is short, cost is low, alleviate resource scarcity, be easy to guarantee that the seashore of construction safety and quality and man-made island underground space building technology seem very necessary.
Summary of the invention
The present invention aims to provide a kind of the alleviation effectively and fills out extra large resource scarcity, improves efficiency of construction, the reduction of erection time, be prone to guarantee construction safety and quality, reduction construction costs, and be applied to the technology that seashore and man-made island underground space structure are built fast.
In order to achieve the above object, the present invention has adopted following technology: a kind of seashore and the comprehensive construction method of the man-made island underground space comprise the steps:
(1) props up the retaining cofferdam planning to build the sealing of building sealing continuously in the seashore of making underground structure or man-made island periphery waters;
(2) the sealing sealing of step (1) is propped up after water pump drainage form in the retaining zone, cofferdam becomes dried operating environment the original state foundation of sea floor is carried out consolidation process or foundation construction;
(3) sand cushion or mattress layer are laid in leveling in the dried operating environment that step (2) forms;
(4) on sand cushion that step (3) forms or mattress layer, carry out underground engineering structure construction such as one or more layers basement;
(5) carry out filling construction at step (4) underground structure periphery and top.
Wherein, said retaining cofferdam comprises one or more of packed sand cofferdam, big sand pocket cofferdam, jackstone cofferdam, cofferdam, clay dam etc.
Need do anti-seepage reinforcing to an above-mentioned retaining cofferdam of not doing the sealing processing and handle, method comprises one or more of seepage proof curtain forms such as impermeable composite geomembrane, high pressure jet grouting antiseepage, grouted cut off wall antiseepage, concrete continuous wall antiseepage, the antiseepage of clay core wall.
Said retaining cofferdam also can be adopted sealing to hold concurrently and propped up a retaining cofferdam, comprise one or more of form cofferdam such as steel sheet-pile cofferdam, major diameter tubular cofferdam, the compound cofferdam of combining structure.
The ground stabilization processing method of said step 2 comprises one or more in the processing methods such as desilting cushion, vacuum method, combined vacuum and surcharge preloading method, flexible pile composite foundation and rigid pile foundation.
Underground structure in the said step 4 comprises one or more in the structures such as cast-in-place concrete structure, precast concrete, assembled on site steel work, pre-manufactured steel structure.
Filling construction in the said step 5 adopts backfilling materials such as sand, soil, the stone that cuts into a mountain, inert material, and job practices comprises method, hydraulic reclamation method, the land propelling backfill method etc. of filling out of throwing.
The present invention compared with prior art has following advantage:
1, develop the underground space that seashore is filled out extra large land-based area and man-made island, the underground space is replaced the required backfill soil body, has reduced native selfweight stress, and considers the buoyancy of water to building foundation, can reduce the requirement for bearing capacity of superstructure to foundation soil.
2, make full use of seashore and marine water-bed mud face absolute altitude is low; Be provided with do not fill out behind the cofferdam sea directly pump drainage do that water forms underground foundation ditch in the weir; The conventional construction techniques that has replaced excavation pit after the first backfill epeirogenetic; Avoided repeating to cause long construction period, the problem that construction costs is high with the excavation operation because of backfill resource scarcity, land-based area backfill.
3, through directly pump drainage girth weir Nei Shui is set behind cofferdam and the seepage proof curtain; Make reinforcing soft foundation and the dried operating environment of underground structure construction formation in the weir; Make the assurance that more is easy to get of underground structure construction safety and quality, avoid that reinforcing soft foundation difficulty of construction under deep jackstone, the layer of sand is big, efficient is low.
4, the dried operating environment in the cofferdam has enlarged the selection of building foundation and underground structure pattern in the ocean structure engineering, has reduced the difficulty of construction and the construction costs of basis and underground structure.
Technology of the present invention can be applicable to the building technology that the extra large land-based area exploitation underground space is enclosed in the seashore neritic area, also can be applicable to the underground space on the man-made island, the building technology in tunnel.Use present technique build the underground space structure of filling out extra large land-based area or man-made island can reduce in a large number fill out sea material demand, greatly the reduction of erection time, reduce construction costs, ensure construction quality and safety.
Description of drawings
Fig. 1 is the sketch map of retaining structure cofferdam and anti-seepage reinforcing curtain thereof, and wherein Fig. 1 a is a retaining cofferdam and a loaded filter, and Fig. 1 b is a retaining cofferdam and a water seepage prevention curtain.
Fig. 2 is a sketch map in the double water-stopping structure cofferdam of retaining.
Fig. 3 be behind the pump drainage water in the cofferdam soft base adopt the sketch map of pile foundation.
Fig. 4 is that seashore and man-made island underground structure are built the sequence of construction sketch map; Wherein Fig. 4 a is a landform elevation before building; Fig. 4 b is the elevation behind the construction cofferdam; Fig. 4 c is the elevation of water in the pump drainage girth weir; Fig. 4 d is the elevation that ground is carried out consolidation process; Fig. 4 e is the elevation that carries out the construction of basis and underground structure, and Fig. 4 f is the elevation that underground structural perimeter and top is carried out filling construction.
Fig. 5 is the comprehensive building technology construction flow chart of the seashore and the man-made island underground space.
The practical implementation method
The present invention implements according to following steps, each figure among the visible Fig. 4 of sequence of construction:
(1) at coastwise reclaiming land around sea shown in Fig. 4 a or man-made island shore protection sideline cofferdam (seeing Fig. 4 b) is set; Can adopt interim type cofferdam and permanent cofferdam; Cofferdam comprises packed sand; Big sand pocket; Jackstone; A retaining cofferdam 11 of a retaining effect is played in cofferdam, clay dam etc.; Cofferdam and this section seashore periphery that tool is only propped up the retaining effect carry out antiseepage to be handled, and adopts composite geo-membrane that loaded filter 12 (shown in Fig. 1 a) is set along the cofferdam axis; Or high pressure jet grouting or grouting formation continuous curtain 13 (shown in Fig. 1 b); Concrete or clay are constructed methods such as diaphragm wall and are formed continuous seepage proof curtain.
The double water-stopping structure cofferdam 14 of a retaining as shown in Figure 2 also can be adopted in the cofferdam, like steel sheet pile, major diameter tubular, composite construction cofferdam etc.
(2) build the cofferdam of sealing continuously, or after making cofferdam and seashore form the water-stop curtain of sealing, the water pump drainage in the cofferdam is done, form dried operating environment, shown in Fig. 4 c.
(3) shown in Fig. 4 d; Soft basic thickness or weak soil characteristic according to the cofferdam inner region; Lay the thick sand cushion of 0.5～1.0m or reinforce shallow top layer weak soil; Adopt method reinforcing flexible foundations such as desilting cushion or vacuum method or combined vacuum and surcharge preloading method then; Perhaps adopt as shown in Figure 3 flexible pile composite foundation or rigid pile foundation 31, above-mentioned ground stabilization processing method can adopt one or more.
(4) on the ground after the reinforcing, lay sand cushion, or lay the sand mattress layer on the flexible pile composite foundation surface, or backfill between the rigid pile foundation cushion cap.
(5) shown in Fig. 4 e, structural shape carries out underground structure 5 constructions under the base area, like the poured in place concrete structure, and assembling steel work, installation precast concrete or steel work.
(6) shown in Fig. 4 f, adopt backfilling materials 6 such as sand, soil, the stone that cuts into a mountain, inert material to carry out filling construction to underground structural top or periphery, can use throwing to fill out methods such as method, hydraulic reclamation method, land propelling backfill method and carry out backfill construction.
The construction process step as shown in Figure 5.