Copyright of Works: Michael Van Valkenburgh & Associates, HNTB Engineering, Applied Ecological Services, Inc.

1. 01
HNTB + MVVA TEAM
hypar-nature
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W h i t e R i ve r
hyper-nature: hī-pər nā-chər
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N a t i o n a l Fo re s t
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a landscape of optimal ecological function at the point of scalar compression
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ic
hypar (hyperbolic parabaloid) vault: hī-pär vȯlt
a modular unit that pairs a doubly-curved surface with a form that depends on a counter-
resistance to the exertion of lateral thrust
This landscape is not for humans. Rather than allowing the primarily visual, aesthetic drivers of landscape
design to determine form, the hypar-nature bridging system is driven by the demands of ecological 10 7
engineering. Instead of attempting to recreate the surrounding nature, the design condenses and amplifies
multiple landscape bands (Forest, Meadow, Shrub, Scree) into habitat corridors that provide connections for
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a larger cross-section of species. The structure itself is a modular and cost-effective system of hypar forms
that allows for minimal site disturbance and easy creation, assembly, and deployment, and can be expanded
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or adapted as migration pressures dictate. By combining a flexible structural solution with an adaptable
approach to broad landscape management, the hypar-nature bridging system offers a new hybrid vision for 5
addressing habitat fragmentation.
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B
la
Distilling, Condensing, and 1
I-70
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Extending Habitat Corridors 2
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Wide Span, Far Reach
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The bridge landscape for West Vail Pass is designed to be a prototype for a regional network of wildlife
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overpasses that addresses larger-scale habitat fragmentation and represents the first phase of reconciling
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the mobility of humans and wildlife. The flexibility and efficiency of the bridge’s structural component makes
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it extremely suitable for widespread use, and its minimally invasive construction allows it to be adapted to any
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location.
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Te n a
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1 Exclusionary Fencing 6 Jack-Tunnel Wildlife Underpass
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2 Bicycle Path 7 Wet Meadow and Water Catchment
il io
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3 Stormwater Infrastructure Connections 8 AGS Rail
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4 Forest, Shrub, and Meadow Planting 9 Expanded Vehicular Traffic Lanes
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5 Hypar Vault Structure Below 10 Breakdown Lane and Snow Shoulder
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Site Plan
N
Migration Corridors Support-
0 50 100 200 Feet
ed by Overpass Network Scale 1 : 1000
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3
2 5
4 9
11 Constructed Forest 44 Geosynthetic-Reinforced Soil 7 7 Wet Meadow and Water Catchment 8
22 Bulk Fill (Class 2) 55 Hypar Vault 8 8 Open Meadow 6 Site Section
33 Lightweight Aggregate Fill 66 Jack-Tunnel Wildlife Underpass 9 9 Shrub Edge Planting 7 Southwest - Northeast

2. observe
02
Thick Infrastructure Complex Habitat Compression
In order to address the complex conflict between roads and wilderness, three-dimensional solutions are required. Hypar nature
Multiple habitat types from the surrounding landscape are The wide foraging bands provide an open field of view while
untangles the conflicting demands of human and animal transportation by bridging both under and over the road, by layering both
selectively distilled and then condensed into a series of parallel narrow forest and shrub bands provide enclosed, covered
driver experience and animal preferences, and by pursuing an adaptable framework for both vegetal and structural systems. In this
bands that act as crossing corridors for various animal species. corridors.
new prototype of landscape and structural collaboration, the performative ground can extend from a light-touch footing to a regional
land management strategy.
Shrub Edge Forest Meadow Forest Scree Seam Meadow Shrub Edge Forest
Overpass Animal Migration
Oreamnos americanus Odocoileus hemionus Canis latrans Cervus elaphus Marmota flaviventris Ovis canadensis Alces alces Lepus americanus Lynx canadensis Ursus americanus Martes americanus
Mountain Goat Mule Deer Coyote Elk Yellow-Bellied Marmot Bighorn Sheep Moose Snowshoe Hare Canada Lynx Black Bear American (Pine) Marten
Landscape Bands
Structural Efficiency
Standard bridge construction requires the use of three created through the use of very simple and easily constructed
individual structural components: abutment, beam and deck formwork. The concept anticipates precast elements similar
High-Ground Topographic
Connection slab. The efficiency of the precast hypar vault module is that it to prestressed AASHTO girders with type designations as a
serves as a combination of all three. The hypar vault module is function of span length.
Hypar Vault Modules
Light Rail + Road Corridor
Enhanced Bicycle Path
Merging Structural Systems Hypar-Vault Module Flexible Formwork
Implementable Construction
With a transport weight of less than 80,000 lbs, the hypar vault crane. The hypar vault modules are set and temporarily
is well within the limits for prestressed beam transport and supported at the median with temporary falsework. Erection
trucking limits. The hypar vault modules are designed to be activities would not require road closures. Construction could
Underpass Animal Migration
lifted and erected using a single rubber-tired mobile hydraulic be undertaken one lane at a time during off-peak hours or at
night, with cross-overs maintaining two-directional traffic.
Wet Meadow Wildlife Attractor
Below-Ground Jack-Tunnel
Connection
Landing Lightly
Placement at the West Vail Pass site intentionally minimizes site is exclusively fill material. The selected positioning
mechanical disturbance of the existing grade by reducing of the structure takes into consideration the existing
the amount of cut into grade. With the exception of the light tree line on both sides of I-70 and the adjacent existing
trenching required for the precast footing, the grade change on grades to minimize the amount of site intervention in the
construction of the bridge and the landform.
Geosynthetic Reinforced Earth
Linking Public and Science 3’-0” Planting Soil Profile
6’-0” Lightweight Fill Hinge at Crown
This design is meant not only to physically stitch together a fragmented habitat, but also to unite the various
Decision- Deploy constituencies that will ultimately be responsible for the success of preserving the Rocky Mountain wildlife. Success lies
makers
in the connection with the general population that can be attained through outreach and education. Rather than relying
ORMATION
DATA
on a single, physical observation point for any one bridge, the development of a digital observation platform would enable
the public to observe a series of overpasses in real-time, as well as access information on particular species, habitats, and
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changes in migration behavior. By allowing the public to engage with the science of ecosystem adaptive management, the
Observe
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Public
design would work toward a shift in society’s approach to operating in wild lands.
Soil Mass Stabilized by Footing
Bridge can Accommodate
Differential Settlement

3. 03
Kit of Parts Constructing Ecology ENHANCED
The hypar module can be deployed in other capacities as 0"
FORAGE
'-
12 BAND
various sites demand. In an expanded option, the bike lane
could be routed through a bike-dedicated tunnel adjacent to but
separated from the road traffic. The hypar vault accommodates E S
'- 0" LAN
the expanded width of I-70 including the AGS rail, three lanes of 36
U ND
traffic in each direction, and a bike lane. O
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Hypar-Vault 0"
0" AN 26'- S
0'- SP AG
18 R
A
C LE
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AN
Bike Tunnel Option S
0" NE
36
'- LA B
ST
U ND
O
ES
TB
RE D
FO AN
W
Sound Barrier
0" JACK TUNNEL 5'-0" Ø WET MEADOW
12
'- B Note: Tunnel to be bored without
WILDLIFE ATTRACTOR
E disturbance to I-70 traffic.
E DG
Retaining Wall
RUB
10'-0"
LANE
BIKE
SH
Fence D
BAN
W
Cultivating Complexity DO D
Animal movement corridors can be induced by understory EA AN
M B
planting of browse grasses and sedges, selective thinning E
of forest canopy, and localized controlled burns. Landscape DG
SH
E
VA
RU
RI
UB
management strategies can create enhanced browse corridors
ES
B
D
ED
starting at the overpass and moving out into surrounding R AN
G
SH
E
B
BA
habitat patches along desired routes.
ND
ST
Meadow Strategy
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FO
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EN
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50
NC
S
'-0
ED
"M
EE
FO
IN
.
RA
R
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SC
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BA
ND
D
AN
Phase 1 Phase 2 Phase 3
Broadcast annual Introduce native Manage for grasses,
cover crop perennial grasses forbs, and sedges B
W
DO
EA
Forest Strategy
50
FO
'-0
M
RE
"M
D
ST
IN
AN
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BA
ND
B
10 E
DG
42
'-0
33 DU
AS
"
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6'- L
P
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EN
0" ES
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UB AN
SP
ENHANCED 30
R
RU
B
Phase 1 Phase 2 Phase 3
'-0
SH
Conifer corridor + 5 years + 10 years
CE
ST D
"
FORAGE
/P
AN
flanked by aspen
IN
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BAND
EN
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CO
FO
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RE
NC
Selective Thinning
75
DG
10
'-0
DE
'-0
"M
Note:
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AS
FO
"
IN
PE
Spruce/Pine forest to be planted
RA
UB
.
N
G
15'-0" O.C.
E
R
BA
Aspen forest band to be planted
SH
ND
4'-0" O.C.
Phase 1 Phase 2 Phase 3
Dense forest with Selectively thin dead Seed with native grass-
dead standing trees trees/ controlled burn es, forbs and sedges
Controlled Burns
FOREST BAND
Phase 1 Phase 2 Phase 3
Dense forest with Selectively thin dead Seed with native grass-
Technical Plan
dead standing trees trees/ pile and burn es, forbs and sedges N
0 25 50 100 Feet
Scale 1 : 200

4. 04
Bridging the Gap
Open Meadow
Tufted hairgrass (Deschampsia cespitosa)
Thurber’s fescue (Festuca thurberi)
Alpine bluegrass (Poa alpina)
Geyer’s sedge (Carex geyeri)
Idaho fescue (Festuca idahoensis)
Shrub Edge
Mountain mahogany (Cercocarpus montanus)
Yellow willow ( Salix lutea)
Red elderberry (Sambuca racemosa)
Bearberry (Arctostaphylos uva-ursi)
Mountain snowberry (Symphoricarpos oreophilus)
Forest
Subalpine fir (Abies lasiocarpa)
Engelmann spruce (Picea engelmannii)
Lodgepole pine (Pinus contorta)
Aspen (Populus tremuloides)
Scree Seam
Common Juniper (Juniperus communis)
Blueberry (Vaccinium spp)
Wood’s rose (Rosa woodsii)
Currant (Ribes spp.)