HK Cavern Construction Masato Shiozawa (UTokyo) T2HKK Workshop - - PowerPoint PPT Presentation
HK Cavern Construction Masato Shiozawa (UTokyo) T2HKK Workshop November 21, 2016 1 Overview of Hyper-K cavern design and excavation is given in my talk Thanks to J.Yamatomi, S. Nakayama, and Hide Tanaka for many slides More
1
T2HKK Workshop November 21, 2016
given in my talk
for many slides
2
Cavern dimension: 76m(ϕ) x 78m(H) Tank dimension: 74m(ϕ) x 60m(H)
3
76000 (cavern) 74000 (water tank) 60000 (water tank) 78000 (cavern)
locates in Tochibora Mine under
yama)
Super-K
(295km) and off-axis angle (2.5deg) to J- PARC beam
(~1755 m.w.e.)
4
1,156m a.s.l. 508m a.s.l.
648m
0M=845m a.s.l.
Hyper-K
5
25yama
←553m a.s.l. ←483m a.s.l. ←423m a.s.l.
Surrounded by many drifts at various levels which enable us to perform geological surveys
The peak was collapsed due to past mining activity. The capacity of rock disposal is estimated ~2 million m3.
6
7
HK
(地下) 坑口 和佐保堆積場 （ずり仮置場） 円山陥没地
地図に道がないので 適当に線（点線）を 書いています
和佐保坑道 (地下)
tunnel between HK site and Wasabo accumulation place.
m3/Tank) will be transported by tracks from HK to Wasabo, and then Maruyama.
mountain peak, capacity of ~2 M m3
Maruyama collapsed Mt. Access tunnel (2.1km) Entrance Wasabo accumula tion place Rock transportation road R
t e 4 1 Kamioka downtown
by major faults
classification, and in-situ stress measurement
measurement
discontinuity survey and rock mass classification, insitu stress measurements were performed.
conducted
8
Tunnel el No.
(5 (553 m a.s.l a.s.l.) .) Bor
ehol
e No.
(5 (553 m a.s.l a.s.l.) .) Bor
ehol
e No.
(4 (483 m a.s.l a.s.l.) .) Bor
ehol
e No.
(4 (483 m a.s.l a.s.l.) .) Bor
ehol
e No.
(4 (483 m a.s.l a.s.l.) .) Tunnel el No.
(4 (423 m a.s.l a.s.l.) .) Tunnel el No.
(4 (483 m a.s.l a.s.l.) .) Tunnel el No.
(4 (483 m a.s.l a.s.l.) .)
ess mea easurem emen ent (4 (483 m a.s.l a.s.l.) .) Initial stres ess mea easurem emen ent (4 (483 m a.s.l a.s.l.) .) Initial stres ess mea easurem emen ent (5 (553 m a.s.l a.s.l.) .)
9
Tunnel el No.
(5 (553 m a.s.l a.s.l.) .) Bor
ehol
e No.
(5 (553 m a.s.l a.s.l.) .) Bor
ehol
e No.
(4 (483 m a.s.l a.s.l.) .) Bor
ehol
e No.
(4 (483 m a.s.l a.s.l.) .) Bor
ehol
e No.
(4 (483 m a.s.l a.s.l.) .) Tunnel el No.
(4 (423 m a.s.l a.s.l.) .) Tunnel el No.
(4 (483 m a.s.l a.s.l.) .) Tunnel el No.
(4 (483 m a.s.l a.s.l.) .)
ess mea easurem emen ent (4 (483 m a.s.l a.s.l.) .) Initial stres ess mea easurem emen ent (4 (483 m a.s.l a.s.l.) .) Initial stres ess mea easurem emen ent (5 (553 m a.s.l a.s.l.) .)
state of sound, intact rock mass
defined by Japanese Central Research Institute of Electric Power Industry (CRIEPI))
referring the obtained data.
10
Model-1 Model-2
Assume the rock mass consists of 100%
Assume rock mass consist of a mixture
rocks
intentionally allocated at the structurally weaker portion (dome and bottom barrel sections) of the cavern
11
CM-class CH-class
4 , 1 9 °
78 65.695° 24.305° CH
(10m)
CM
(21m)
CH
(50m)
CM
(14m)
CH
(17m)
CM
(13m)
6 5 , 8 1 °
65.695° 24.305° CH
(uniform)
Summary of rock classification
A~CH classes CM~D classes
553m a.s.l.
(-300mL)
>95% <5%
483m a.s.l.
(-370mL)
~68%
(57~78%)
~32%
(43~21%)
→ Ref. for Model-1 → Ref. for Model-2
6 5 , 8 1 °
6 5 . 6 9 5 ° 24.305°
Model-2 rock conditions
12
Cavern geometry
stability analysis
(ex. at an excavation step)
Model-1
for both Model-1 and Model-2 rock mass conditions
13
Plastic region depth (without support)
(45° slice) (45° slice)
Cavern support (PS-anchors)
(45° slice) (45° slice)
Model-1 Model-2
CM-class CH-class
65,810° 78 65.695° 24.305°
CH
(10m)CM
(21m)CH
(50m)CM
(14m)CH
(17m)CM
(13m)65,810° 78 65.695° 24.305°
CH
(uniform)Model-2 Model-1
7m 4.5m 12m 14m 10m 9m
14
Upper access tunnel Lower access tunnel Outer incline tunnel ‘Wasabo’ access tunnel
N1km
Upper access tunnel Lower access tunnel
Dome section approach tunnel Outer incline tunnel 2nd level approach tunnel 4th level approach tunnel 2nd water room 1st water room
Wasabo access tunnel
Top level approach tunnel
Wasabo access tunnel Approach tunnels (one cavern)
cavern construction
for the waste rock transportation
15
Milestones Items Major construction Wasabo access tunnel Preparatory construction Temporary yard Shotcrete, waste-water facility Access tunnel Upper access tunnel Lower access tunnel Outer incline tunnel Upper access ~ water room Water room ~ 1st level approach 1st ~ 2nd level approaches 2nd ~ 3rd level approaches 3rd ~ 4th level approaches (end point) Tunnels connected to water room 1st water room entrance 1st water rm (preceding excavation) 2nd water room entrance 2nd water rm (preceding excavation) Measuring tunnel Water room excavation 1st water room Upper section Lower section 2nd water room Upper section Middle section Lower section Cavern excavation Dome section Dome section approach Dome section excavation Barrel section (1st stage) 1st level approach tunnel Preceding excavation 1st stage excavation Barrel section (2nd stage) 2nd level approach tunnel Preceding excavation 2nd stage excavation Barrel section (3rd stage) 3rd level approach tunnel Preceding excavation 3rd stage excavation Barrel section (4th stage) 4th level approach tunnel Preceding excavation 4th stage excavation Reinforcement of road to Maruyama Wasabo entrance construction Begin cavern excavation Complete cavern construction PS-anchor & water room excavation proceed in parallel PS-anchor & approach tunnel constructions proceed in parallel Cavern construction with two shifts (Day- and Night-shifts: 24hrs)(See HKDR for details)
Tunnel construction Water room construction Cavern construction
Dome section Barrel section
(~23 months) (~36 months)
(parallel w/ cavern const.)
Lankford, Masaki Mori, Toshinori Mori, Katsunobu Oide, David Sinclair, Jim Strait, Yifang Wang, and Jiro Yamatomi
Kazuto Seto, Nozomu Kotake
16
The committee believes that the current cavern design is reasonable at this conceptual
expertise and subjecting it to review by an independent committee of experts is the correct one to follow. The committee strongly encourages an early and complete geotechnical investigation and thorough analysis of the results, which will allow the feasibility of construction of such large caverns in this rock mass to be better established, improve the understanding of the requirements and cost for excavation and ground support, and help understand the risks due to potential creep of the cavern dimensions after the tank has been constructed inside it.
17
5
年 月 日 合成地震記録による反射波の三次元重合処理結果の比較（第一案と第二案の比較） 神岡鉱山栃洞坑内に存在が確認されている 断層を考慮し、下図に示す測点配置において受発振した場合の合成地震記録を作成した（次頁参考 図参照） 。得られた合成地震記録を元に、直線波線経路に基づく三次元重合処理を行った。なお、地震記録は次の 種類作成した。 第一案：対象範囲（黄色の枠で表示した領域）をほぼ網羅する測定配置（ ～ までの６坑道に受発振点を配置する） 第二案：測定範囲限定する（ 北向、 鉛断層付近測線廃止） 図１ 合成地震記録による等走時面重合結果（左：第 1 案、右：第 2 案） 結果：第一案では対象領域内の各断層からの反射面を把握できる可能性が高いと考えられる。一方、第二案では、規模の小さな断層（例えば緩めの 断層等）及び規模の大きな断層ではその広がりが十分に把握できない可能性がある。 以上
m L 円 山 向
wave in the existing tunnels at -200mL, -300mL, -370mL (and -430mL)
in ~300m x ~300m area (entire area of candidate site)
if any in the candidate site
[Simulation]
Wish to pin down the best candidate place
約72000ｍ とする。
2 3 3
約72000ｍ とする。
2２． ３ｔ/
A’ A 地表凹面
斜面安定解析断面線 斜面安定解析用ボーリング （No.1） 「崩壊ずり」 の埋設状況確認用ボーリング （No.2）
ボーリング位置図、 斜面安定解析断面位置図
※上記図の赤青エリアは、 掘削ずりの当該箇所への堆積計画案である。 右下から左上に向い階段形状にて積み上げる案にて解析を 行う こ と とする。 掘削ずりの堆積後の単位体積重量は、 2.3t/m とする。 想定ずり量は、 約260万m とする。 青＝平場(5m)、 赤=勾配(安息 角25度高さ10m)、 最上部の青は全面平場とする。 同エリアの水平投影面積は約72000m とする。 但し、 上記図は計画図であり、 調査の際は神岡鉱業株式会社へのヒアリング及び現地確認の上、 作成する事。
3 3 2
3’～3 3’ 3 斜面安定解析用及び 「崩壊ずり」 の埋設状況確認用ボーリング位置図 （断面） 3’～3断面に投影 :
the rock
8
No.1 No.2
100m
Many tunnels used for mining
(not in use now)
Crashed rock and sand
buri
Cross section
18
19
construction and construction schedule have been established based upon
three levels
disposal strategy
conducted aiming