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Construction of a Retaining Wall

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Construction of a Retaining Wall Cut and Cover Tunnel Construction of a station by cut & cover method Road decking panel Rectangular shaped tunnel Support Retaining wall June 30th 2016 Lecture at Waseda Univ. Shinji KONISHI 1 Types of Tunnel & Construction Methods What’s Tunnel? What’s a tunnel made of ? 2 Types of Tunnel Cut & Cover Tunnel Shield Tunnel Mountain Tunnel Difference of ground Difference of construction method 3 COMPARISON-1.Outline of construction methods NATM Shield Cut & cover ・Shot Crete， Steel support， ・ Segmental Lining. ・Earth-retaining wall, Rock Bolt Main body ・The skin plate of the shield machine, outer backfill layer of the shield and the segmental ・The ground ・ Making full use of the support the wall of the tunnel. excavated from the natural support function of surface to build the the surrounding ground tunnel at the desired depth. Then the ・Closed-type shield stabilizes the ・Prerequisite condition is excavated earth is face using earth or slurry to that face remains brought back to counter earth or hydraulic standing when excavated restore the surface. pressure. 4 COMPARISON-2.Countermeasure for underground water NATM Shield Cut & cover ・When there is water ・Usually, closed ・Countermeasures such as deeper inflow that affects the self- type shield does penetration of earth retaining wall, support of the face or not required groundwater reducing method, stability of the ground countermeasure soil improvement etc. are usually during excavation, water s, but the open necessary to overcome boiling or sealing method such as by type does. heaving. deep well, well point, or drainage tunnel is necessary. Natural water level. Deep well. 5 When a structure is needed to construct in underground, 1 If there is no limitation of the ground surface and surroundings, Ground surface New structure 6 When a structure is needed to construct in underground, 2 If there is no limitation of the ground surface and surroundings, New structure ⇒ Open cut method Cheaper, Faster 7 When a structure is needed to construct in underground, 3 If there is limitations of the ground surface and surroundings, Road decking Suspended guard Strut Earth-retaining wall Wale 8 What ‘s an earth-retaining structure? An example of retaining wall >Prevent the collapse of surrounding ground and inflow of ground water. Main body >Compose with retaining wall and support (Strut, wale) Wale Strut >The structures and construction works are called Earth-retaining structure and earth- retaining support. Earth-retaining wall 9 Composition of earth-retaining structure (Solider pile with lateral lagging) Jack cover Bolts of cross part Strut Jack Wale Angle brace Center pile Bracket Solider pile Pile heading Lateral lagging 10 Types of earth-retaining wall - 1 An easy method Weak Cheep For shallow tunnel Fast >-20m Solider pile Lateral lagging U shaped steel sheeting pile （a） Solider pile with lateral lagging H shaped steel sheeting pile （b） Steel pipe sheeting Z shaped steel sheeting pile （c） Steel pile sheeting 11 Types of earth-retaining walls - 2 An advanced technology Rigid, Strong Large scale For deep tunnel Expensive Colum-type: >-50m Long time Diaphragm wall: >-150m Staggered layout （f） Slurry solidified diaphragm wall Overlapping layout （d） Column-type underground diaphragm wall Installed in every hole Installed in alternate hole （e) Underground diaphragm wall （g） Soil-cement diaphragm wall 12 Execution of earth-retaining wall Soil-cement diaphragm wall SMW polyaxonal mixing auger machine Crawler crane Plant Corer material Excavator (H-shaped steel) 13 Types of support methods- 1 An easy method For shallow tunnel Cheep Useful underground space Fast Sｔruts Strut Soil retainingWales Soil retaining wall wall Embedded part Bottom of excavation （a） Unbraced soil retaining work （b） Strut type soil retaining work Tie-load Free length of anchors Popular type Wale Wale Inconvenience腹起し space Fixed length of anchors Bottom of excavation Anchor-pile Useful undergroundSoil space retaining wall Land behind the wall is needed （c） Ground anchor soil retaining work （d） Tie-load with anchor-pile type soil retaining14 work Types of support methods- 2 Soil-cement diaphragm wall Ground anchor Corer material Wales (H-shaped steel) Bracket Plinth Soil-cement diaphragm wall Corer material (H-shaped steel) 15 Procedure of cut and cover method Presented by Tokyo Metro Co.,Ltd. 16 Standard Structure of a Tunnel Station tunnel Running tunnel Single track Double track 300 450 6,700 9,800 Cut & cover tunnel Shield tunnel 17 Cut & cover method Construction of a station by cut & cover method Road decking panel Rectangular shaped tunnel Support Retaining wall 18 Construction Methods of Cut & Cover Tunnel Standard Construction method Upside-down Construction method Stiff ground (Simple procedure) Soft ground (Complex procedure) Center pile Center pile Slab of upside-down construction Column-type underground diaphragm wall Underground diaphragm wall 先行エレメント 19 後行エレメント 後行エレメント Standard construction method Excavate from surface to bottom. Then, construct the body. Upside-down Construction Method • A slab is constructed in advance, because it is used for a high-rigid strut restraining deformation of the retaining wall. • The method is applied in the case of construction in the soft ground or with deep excavation. • If the upper floor slab is constructed by the method, it is advantageous to back fill in early stage. 10:40～12:10 Road decking panel Underground Diaphragm wall Center pile Upper Floor Slab Construction of the upper floor slab Middle Floor Slab Construction of the middle floor slab Excavation Base Slab Construction of the base slab Construction of the inner part Procedure 1 of a cut & cover method-1 １．Preparation ２．Removing a sidewalk ３．Construction of a retaining wall 35 Procedure 2 of a cut & cover method-2 ４．Road decking ５．Excavation, Setting earth-retaining support ６．Utility movement and protection 36 Excavation under a road decking 37 Carrying out the muck-1. 38 Carrying out the muck-2. 39 Setting supports, Slab of upside-down construction 40 Procedure 3 of a cut & cover method-3 ７．Construction of tunnel 41 Placing concrete 42 Procedure of a cut & cover method-4 ８．Restoration of the utilities ９．Back filling １０．Removal of the road decking １１．Removal of heading part of piles １２．Restoration of the road １３．Setting facilities 43 An example of the special cut & cover method Nanboku line Roppongi-ichome station Metropolitan Viaduct of Expressway Metropolitan Expressway is close to new station. Underground diaphragm wall Underground diaphragm wall Plan view of the Roppongi-ichome station 首都高速道路都心環状線 Cross underground Diaphragm wall In the case of existing underground water with high pressure, if you excavate lower part of below underground water level, Underground Underground water water The bottom surface of the cutting heaves due to pressure of underground water. heaving Underground Underground water water When base of excavation is broken, large deformation of the surrounding ground occurs Underground Underground water water Underwater Excavation Method Pour water to underground water level and excavate with keeping water pressure balance Underwater excavation Underground Underground water water Underwater Excavation Method Underwater excavation Underwater concrete Cleaning of wall and base Removing water 6:20～10:39 Change of a cut & cover method Back ground >Environment Preservation ＞Low noise construction method, (Noise, Vibration, Lowering of ground water level) Low vibration construction method. ＞ >Larger and deeper of structures Improvement of preventing water leakage capacity. >Mechanization of construction ＞Keep of a space for construction. ＞Countermeasure of a heavy load. >Enlargement of traffic on the road Technological innovation 51 Change of a cut & cover method 1940 1950 1960 1970 1980 1990 2000 2010 Marunouchi line HIbiya line 東 Touzai line 京 メ Chiyoda line ト ロ Yurakuchou line Hanzoumonn line Nanboku line Fukutoshin line Soldier pile with Driven pile Bored pile lateral lagging method Single axis, Multi axes, Column-type underground Reinforcing bar Single axis, H-shape steel diaphragm wall basket H-shape steel Underground The I.C.O.S. method Reinforcing bar Steel material diaphragm wall Wooden basket Combined use of temporary wall Steel material Support Pine log Ground anchor A thirty-centimeter square piece of lumber 52 Road decking Wooden Steel A record of subways in Tokyo Opening開業年 year（年） 昭和 平成 193510 194520 195530 196540 197550 198560 19956 200516 0 91 10 Ginza銀座線 line Marunouchi丸の内線（17lineｍ，昭和17m34 1959年） （16m16ｍ， 1934昭和 9 年） 20 日比谷Hibiya線 line（23ｍ，23m昭和 196439 年） Touzai東西線（line26ｍ，26m昭和 196742 年） 30 有楽町線（32ｍ，昭和 49 年） Chiyoda千代田 line 線 Yuurakucho Line 32m 1974 ) （335m5ｍ， 1969昭和 44 年） ｍ 40 ( Hanzoumon半蔵門line 線 南北Nanboku線（43lineｍ，平成43m8 1996年） 度 （39ｍ，昭和 57 年） 深 39m 1982 都営Ooedo大江戸line線 Depth 50 （49m49ｍ， 2000平成 12 年） 60 53 Pile driving (Single pile) Marunouchi line Hibiya line Piles of column-type underground diaphragm wall (Chiyoda line) Under the Shinobazu street Under the Ikenohata street 55 Column-type underground diaphragm wall 56 Pile of Column-type underground diaphragm wall Borehole by multi- axes auger Yurakucho line, Toyosu 57 Underground diaphragm wall The I.C.O.S. method (Reinforcing bar basket) (Marunouchi line, Hounannchou) 58 Cross section of the I.C.O.S. method (Marunouchi line, Hounannchou) 59 Underground diaphragm wall Hanzoumon line, Sumiyoshi station Reinforcing bar basket 60 Support （Strut, Wale) (Wooden support) Pine log Wooden support (Marunouchi line) Support
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