History of the Structures

Poly Canyon is the epitome of Cal Poly’s Learn by Doing philosophy in action.  This area came into existence when George Hasslein, the first dean of the College of Architecture and Environmental Design, wanted to show off Cal Poly student projects and provide a location for large scale experimental structures. Many generations of students have worked in these hills with some of the student-built structures dating back to 1964. These structures set Cal Poly apart from any other university.


BBQ Pit

bbq pit

Built in the 1970s or 80s the BBQ area used to be covered by a corten hood with aluminum connections and steel channels. This hood was later removed because of the difference in materials. The chairs close by are EDES class projects and projects related to Design Village.


Blade Structure

First constructed in 1963, Poly Canyon’s Blade Structure is the oldest structure originally built in the canyon. Completed by students Steve Gilmore, Mark Haselton, Dan McMann, and Ken Minor, it was one of the first structures on campus to test post-tensioning methods. After many years of deterioration, the blade structure was reconstructed in 2003 by students Ben Green, Robert Pacheco, Elley Arinez, Susan Smilanich, Jeff Messana and Jon Voorhies, with the assistant of Architectural Engineering Professor Nick Watry. Design work required the students to modify calculations to abide by the updated building code and create a more structurally sound project. Three of the original students who worked on the project returned to Cal Poly to help them achieve this, providing the students with advice, funding, and knowledge from experience. In 2006, the Post Tensioning Institute awarded the design team with an Award of Excellence for their design of the new Blade Structure.

Original Blade Structure. Image from the Paul and Verla Neil Resource Center, circa 1970

About

The blade structure has gone by many names over its sixty-year existence, including the petal structure, the Cal Poly memorial, “earth forms,” the concrete flower, and a sculptural study in pre-stressed concrete. Originally constructed in 1963 by students Steve Gilmore, Mark Haselton, Dan McMann, and Ken Minor,this structure tested newly-discovered post-tensioning methods. After a few decades in the canyon, the ‘petals’ deteriorated and collapsed. Nearly forty years after completion, the blade structure was rebuilt by students and Professor Nick Watry, as well as three of the students who worked on the original structure. Some of the original fractured petals still remain around the new structure today as a reminder of the original design.

Pre-stressing, Pre-tensioning, and Post-tensioning

The blade structure is the oldest structure originally built in Poly Canyon, as well as one of the first structures on the Cal Poly campus to utilize pre-stressed concrete. Other campus buildings that employ pre-stressing techniques are the Julian A. McPhee University Union and the Housing South parking structure.

Pre-stressing is used to force concrete into a constant compression state by putting an axial compressive load on the given member. Tension cables are used where beams or slabs are expected to be under a high tensile load, often times the bottom of the member, to “pull” the member together into compression. This creates a cambered member, enabling it to resist higher flexural loads by limiting the tension experienced on it. Concrete naturally has a higher capacity in compression than in tension which allows this method to support larger loads.

Image from omibnotes.blogspot.com Pre-stressing concrete, or creating an axial compressive load in the member, can be done two ways. The first, pre-tensioning, involves pouring concrete around stretched, taught cables, then releasing the tension in the cables once the concrete has fully cured. The cables “snap” back to their original shape, similar to a rubber band, and pull the concrete together to form an internal compressive force within the beam or slab. The second option, post-tensioning, consists of casting concrete with small, tunnel-like cavities that will be threaded with cables once the concrete has cured. The cables are kept taught by anchors at each end of the “tunnels.” This method also forces the concrete into compression to withstand greater loads. The Blade Structure in Poly Canyon utilizes post-tensioning methods.

Deterioration

Rumor has it that cattle used the petals on the Blade Structure as a rubbing post, eventually leading the project to deterioration. The exact year the petals collapsed is unknown, but they likely fell independently over time. This is largely due to the original design not accounting for these upward loads. When the students first post-tensioned this structure, they only placed reinforcing steel on the exterior curve of the blades to account for gravity, wind, and potentially seismic loads. As cattle push up against this structure, they create a force in the opposite direction of the loading condition mentioned, essentially mirroring the designed loads. To resist this force, there equally would have to be mirrored reinforcement, or reinforcing steel along the interior curve of the blades as well.

Redesigning the Blade Structure

In 2003, students Ben Green, Robert Pacheco, Elley Arinez, Susan Smilanich, Jeff Messana and Jon Voorhies, along with Architectural Engineering Professor Nick Watry, began the redesign of the blade structure. Three of the alums who worked on the original project, including Steve Gilmore, Mark Haselton, and Ken Minor, returned to help with the reconstruction.

The design team pictured with the newly completed Blade Structure. Image from the Cal Poly Architectural Engineering DepartmentUsing more accurate post-tensioning information and new materials, the group revised and edited the earlier calculations. Unlike the original structure, the new blades were designed as a catenary arch, combining both structural performance and artistic quality. A catenary arch is the unique shape an arch takes when supporting only its self-weight (one of the most famous examples of this is the Gateway Arch in St. Louis, Missouri). This curvature enables the petals in the blade structure to be in a constant compressive state without any internal tension forces.  However, the design team still included post-tensioning methods in the renovation of the structure for safety purposes and to keep the vision of the original design. In 2006, the students won an Award of Excellence at the Post Tensioning Institute Awards for their design of the new Blade Structure.


Bridge House

The Bridge House is perhaps the most varied-use structure in Poly Canyon. Begun in 1965 and completed by 1968, this structure was one of the first nation-wide to utilize Cor-ten steel. This allowed the students to expose the steel and recreate the designs of Craig Ellwood, a prominent architect of the time. Architectural and Architectural Engineering students originally designed this to be used as lodging for visiting guest lecturers and critics. Over the years, it has been adapted into an architecture studio and canyon caretaker’s home. Today it functions as a seismic testing facility for Architectural Engineering students.

About

Bridge House. Image from the Paul and Verla Neil Resource Center, circa 1970.The Poly Canyon Bridge House was completed in 1968 by students Ronald Davena, Joel Dean, Robert Garlow, Raymond Hilken, Lui Horstmeyer, James January, Lloyd Suehiro, and Thomas Wiggin under the guidance of faculty members Kurt Holder, Bruce Campbell, and Tom Matles. The project fell in line with many objectives the students wanted to achieve, including testing the newly discovered Cor-ten steel, designing a structure to span over the arroyo, and creating a housing facility for important campus guests.

The original senior project proposal intended for the Bridge House to be used as short-term housing for guest lecturers and critics visiting the campus. Over the years, the building has been used as a canyon caretaker’s home and an architecture studio (need to find source to confirm). Today it serves the Architectural Engineering department as a seismic testing facility. Each exterior brace is removable to reconfigure the system to resist seismic loads. Small vibrations are sent throughout the structure while the deflections are closely monitored. After damage to the glass walls, the structure was enclosed with plywood panels. In 2015, the Canyon Days Committee began a handrail project to open the structure once again. This is expected to be completed by summer 2017.

Inspiration for Design

The Bridge House was modeled after the designs of Craig Ellwood, a prominent Los Angeles-based architect from the 1950s through the mid-1970s. In his early career, he began to explore the idea of creating a building that functioned like a bridge, spanning over rivers and uneven landscapes. This would enable sites commonly thought of as unusable to be developed. The Cal Poly students modelled the Bridge House in Poly Canyon after projects created by Craig Ellwood Associates, such as the Chamorro House (Steel Bridge House), commissioned in 1962 (unbuilt), and the Frank and Polly Pierson House #2, commissioned in 1963. In 1976, Craig Ellwood Associates completed the Art Center College of Design in Pasadena, CA, which closely mimics the geometry of the Poly Canyon Bridge House, spanning nearly 4 times as long over the arroyo.

This structure marks the first use of Kaisaloy 50 CR steel from Kaiser Steel Company on a large scale. Because very little was known about the material durability in structural purposes, all of the weathering steel was donated to the students, allowing the company to test the product while providing students the senior project opportunity. Kaisaloy 50 CR is a form of weathering steel, also known by the name Cor-ten steel. The steel is chemically composed with additional metals such as carbon, silicon, copper, and nickel, among others. Weathering steel is designed intentionally to rust when exposed to weather to create a protective layer that resists any material degradation that could lead to a loss in strength. Another way to think about it is like a vaccine; a small, deliberate dosage prevents a larger and more dangerous effect later on. The students who designed the Bridge House received an Award of Excellence from the American Institute of Steel Construction.


Cantilever Deck

 

cantilever deck

1989-1990

Students: Rowan Hernandez, Kim Throndson, John Morrena, Lee Benson

Advisor: George Hasslein

In this particular structure, nothing touches the ground. The load is transferred by cables up to the mass then back down to the ground plaque on the base. The mass of the structure was built by only one female and one male architecture student at the sport shop, however, others helped with the welding. The deck uses strong anchors to demonstrate the use of a cantilever.


Cardinal Direction


Student: Brian Milton, ARCH

This artifact along with the serenity wall line up the cardinal directions.


Gunite Bridge

Gunite Bridge

Gunite Bridge

Gunite bridge

Gunite bridge
Gunite Bridge
1965

Inspired by the Shell House, this is a pretension, post-compression bridge. The structure was created using two posts that held the wings pulled by tension cables, two footings at the end of each side of the bridge, and support legs that extended from the posts into the footings on the ground. The structure consists of reinforced steel, tension cables and metal lath covering the structure forming the skeleton. The infrastructure was sprayed with concrete using a Gunite machine. Once the concrete dried, the tension cables suspending the pillars were cut, and the structure was now in compression. A veneer of white sand and cement covers the bridge for aesthetic purposes. 


Earth formed Restrooms

1972

Students: Glen Jackson, Robert Del Bianco, Ralph Nafzgar

Advisor: Al Draves

These concrete bathrooms used an earth mound as formwork for the curved roof.  Once the roof had cured the soil was excavated and the bathrooms were plumbed. One of the caretakers that lived in the Underground House used to have to come down to these restrooms before the outhouse was added.


Entry Arch

entry arch

 

1976

This gateway to the Canyon was constructed with a steel frame inside and rock overlay. The stones are made of serpentinite that produce natural asbestos. The students who built this structure watch over you as you enter. Can you find their terracotta faces?


Fratessa Tower

fratessa tower

2004

Students: Rachel Martin, Justin Wei, Michael Braund, Eric Mcdonnell, Tanya Worotko, Adam Stagnaro

Dedicated to the late ARCE department head, Paul Fratessa, the Fratessa Tower provides visitors a unique perspective of the sweeping views of the Canyon.  It replaces a previous observation tower whose structural support was based upon an incompressible water column. Due to leakage issues this structure was decommissioned, however the new tower was built on original foundations. The foundations and precast concrete columns seen adjacent to the Fratessa Tower was another incomplete project that is assumed to look something like the current tower.


Geodesic Dome

Constructed in 1957, Cal Poly’s geodesic dome marks one of the first of its kind built on the west coast. Geodesic domes are remarkably strong and lightweight with a minimal amount of material, making them widely popular during the 1950s and 1960s. Five students built the dome from the design theory of R. Buckminster Fuller after a lecture of his the year before on these domes. The structure originally stood on campus as the entrance to the architecture building before being transported to Poly Canyon. Today it remains a campus landmark to remind students of a time when student projects were not limited to size or scale.

After an inspiring speech by renowned architect R. Buckminster Fuller at Cal Poly in 1956, a group of five architectural engineering students came together to build his patented “geodesic dome.” This would become the first permanent dome of its kind in the western United States. For several years after its construction, this student project was the largest dome west of the Mississippi for many years at 50 feet in diameter and 25 feet tall. Completed by students Richard Neill, William Roth, Donald Mills, Samuel Peterson, and Don Trunklage, the dome utilizes over 19,000 nuts, bolts, and washers, and over 1 mile of 1” diameter war surplus boiler pipe.

History of Geodesic Domes

 Students often climbed the geodesic dome to take a break from schoolwork.  Image from El Rodeo Yearbook, 1958The first geodesic dome was built shortly after World War I by Walther Bauersfeld, but it wasn’t until nearly 20 years later that the structure became popular in the United States by Buckminster Fuller. Known as an “architect - author - philosopher - mathematician - engineer” by those who attended his 10-hour long lectures, Fuller patented the idea in 1954 and shortly after saw a boom in geodesic domes throughout the country in the following years, including the one built on campus in 1957. After World War II the United States suffered a shortage in housing. Geodesic domes were a brilliant solution to this problem, being easily-constructible from excess war materials and able to be built nearly anywhere in a short amount of time. These domes never grew widespread in the housing market despite their demand and interest, due to the constant negotiations between union construction workers, designers, and stockholders. Today they are used throughout the world as civic centers and public spaces. A few of the most popular domes are Spaceship Earth and the Walt Disney World EPCOT Center in Bay Lake, Florida, United States, the Zeiss Planetarium in Jena, Germany, and the Climatron greenhouse in the Missouri Botanical Gardens in St. Louis, Missouri, United States.

Geometry and Structural Integrity

Geodesic domes are constructed with a series of triangles that form hexagons and pentagons. Most often the triangles form hexagons, and a triangle-formed pentagon is spaced between these hexagons at intervals between 2 and 8 struts, including those in the pentagon (see figure). These domes are unique in the sense that the larger they are, the stronger and more lightweight they become, uncommon to most structural systems. In comparison to rectangular- and square-framed structures, they enclose a larger volume of space with a smaller surface area.

 Geometry of a 4V geodesic dome. Struts are highlighted in red. Image from www.ziptiedomes.com

Cal Poly’s Geodesic Dome

 Geodesic dome in its previous location near the Cal Poly architecture building. Image from University Archives The Geodesic dome is by far the oldest structure in the Experimental Design Structures laboratory in Poly Canyon, outdating the founding of the laboratory itself. Potential uses of the dome were discussed soon after its completion in 1957, including use for a chapel or a gathering space with a fully functioning HVAC system. Prior to its relocation, the structure stood as the entrance to the architecture building until October 1963 1963 (since replaced by the Clyde P. Fischer Science Hall and A-1 administration parking lot). In May earlier that year, a group of rowdy students moved the dome with sheer human strength from the architecture building to the cafeteria patio area as a prank on Poly Royal weekend. After months of deliberation and with the newly-founding outdoor laboratory space, the structure was finally moved to its permanent home in Poly Canyon. During events like Design Village this student project serves as a sound stage for disc jockeys because of its excellent acoustics, due to the geometry of domes. Today the structure functions as a symbol of the “learn by doing” philosophy.


Greenhouse

GREENHOSUE

1983-1989, fully operational 2006-2008

Student: Mark Jenefsky

Advisor: Jens Pohl

Although not finished, the plans of the Greenhouse were quite innovative with the intention to install an automatic watering system and venting system, along with more plant beds to innovate the idea of a standard greenhouse. The black grate on the back was meant to store water that would be heated by the sun. The heat would then be released in the evening to maintain the same temperature throughout the day. The stack ventilation allows heat to rise then the catchers rotate to optimize ventilation. These rotating catchers make the Greenhouse the only dynamic structure in Poly Canyon.


Hay Bale Arch

2004

Straw is used inside of this structure which provides cheap and surprisingly good insulation abilities. The "window of truth" gives you a glimpse of the straw that makes up the structure. This is perhaps the only double barrel arch of this sort. The students tried not to have any support structure while building, but in the end had to hold the keystone hay bale in place before building around it.


Meditation Bench

Student: Brian Milton, ARCH

This bench was built along with the serenity wall by an architecture student who wanted to construct a meditation space where he could relax while completing his final year thesis.


Modular House

Modular House

1964-1973

Students: Paul Thoryk, John Edmiston, Glen Jackson, Tom Bylund, James Jones, Richard Pata, Lorin Smith, Jerry Tucker, Dennis Turner

Advisors: John Edmisten and Don Koberg

This structure was built as an experimental house with a steel frame and wood infill. The name comes from the fact that the building is on an eight by eight module vertically and horizontally in order to avoid cutting any lumber. An addition was constructed at 45° to the original layout.  It has been difficult to keep this structure waterproof because of the expansion differences of the materials so old signs were used as flashing on the back side. The last caretaker to live in the canyon lived in this house.


Palm tree


The use of dissimilar metals on the top and bottom were used with the intention of having the different expansion/contraction rates of each cause rotation.


Pole Building

POLE HOUSE

1980-1989

Students: EDES Class Project

Advisor: Randy Detmer

This structure is built on caissons in response to the sloping site. It does not touch the ground. The load from the building transfers into the caissons and into the bedrock. The area in front of this structure has been as a staging area for many projects in the canyon.  Can you find the test footing for the Tensile Structure?


Poly Pavillion


1985

Students: Alfredo Alcaraz, Armando Paez, Blanca Guerra, Bob Green, Brad Bishop, Brett Beeman, Chi Pham, Cindy Smith, Dave Hernandez, Frank Maskiewicz, Jim Low, Joe Michale, John Smith, Ken Brehmer, Ken Schumann, Ku Divita, Pete Chavez, Randal Brunson,Ricardo Arevalo, Stan Smith

Advisor: Jake Feldman

Built by an ARCE class, the Poly Pavilion is constructed of precast concrete segments which were constructed in the concrete yard of Engineering West and transported to the Canyon by truck.  Segments were bolted and welded before joints were packed with grout.  The structure is supported by arching action between the foundations.


Serenity Wall

serenity wall

Student: Brian Milton, ARCH

The student had the motto “out of sight, out of mind.” He wanted the wall to fade into the landscape. The redwood planks make this structure weather resist and relatively maintenance free while complimenting the natural surroundings and providing an entry to the timber bridge and meditation bench beyond.


Shell House

shell house

1963-1964, 1975

Students: Larry Gangwisch, Ronald James, Raymond Ketzel, Roger Marshall, David Wright, James Zimmerman

Advisors: George Hasslein, Wesley Ward, Harvey Koehen

The exterior is the oldest structure still existing in the canyon. The Shell House's distinctive roof was created by putting up a center pole with cables hanging down, then spot welding on wire mesh, then a mortar-like substance (shotcrete) was sprayed onto the mesh, and then the pole was removed. This was the first use of shotcrete so the students did not know that while spraying they must be grounded to the structure, so they got shocked the first few times they tried to do it. The building is only supported in 3 spots on the ground. The interior was built after the concrete shell. An operable water fall used to flow underneath the stairs to the loft. The fireplace was very innovative in the fact that while burning, cold air would flow through the bottom pipes and get heating by the fire before flowing out the top and heating the room. Caretakers used to live in this house.


Stick Structure

1976, renovated in 2009

Original Team: William F Martin, Brian Gottlieb, Dan Morita, Michelle M. Pettit

Faculty Advisor: Jake Feldman

Project Coordinator: William R. Phillips

Renovated by Alex Barnes, Blake Roskelley, Katie Blaesser, Justin Porter
Advisors: Abe Lynn and Cole McDaniel

The Stick Structure was originally constructed to be used as a life size structural stability model in which students could learn about load flow and stiffness of different structural configurations.  While the structure was intended to be deconstructed and reconfigured on a regular basis, this was never done and after 30 years the structure fell into disrepair.  The structure was deconstructed and rebuilt in its current configuration with low maintenance materials.


Sun Dial

1971

Advisor: John Stuart

Poly Canyon is an experimental testing lab, projects that collapse or are not finished are not considered failures, but rather leave room for growth and discovery in the learning field. This post-tensioned structure collapsed in the 1990s most likely due to so many people climbing on it.


Techite Bridge

1973

Students: Robert Purdy, Robert Mac Luan, Merilee Amy

The bridge was built using a type of fiber-reinforced plastic mortar by civil engineering students.


Tensile Structure

2002-2003

Students: Kiren Kelly-Sneed, Theresa Zaro, Royce Chow

Advisors: Abe Lynn, Michael Lucas, Walt Tryon, Richard Zweifel

All shop drawings and calculations were done by the students and it cost about $20,000. The 12 footings that hold the cables all connect underground for strength and stability. The purpose of this structure was to provide shade for the annual design village project held in the canyon every year. A structure using fabric as a material. Royce Chow, who worked on the project as a student, later had his marriage ceremony beneath the structure.


Timber Truss Bridge


1994

Derek Bonsper, Josh Randall, Fred Sobottka, Mike Willis

In 2015, this bridge was retrofitted by former caretaker Brian Planas, first-year ARCH student Keigen Langholff, and others attending the Canyon Days event. Shortly after, Langholff passed away in a vehicular collision while driving home at the end of his first year of college. He expressed great interest in joining the Committee, but never got a chance to. He will be missed greatly.


Underground House

1982

This structure was once underground and the holes on top were used for skylights. Problems like structural leaking due to the natural spring located further up the hill caused it to be dug up from the ground. A caretaker used to live here. The outhouse was a later addition.


Water Tanks

1969 renovated in 1998

Student: Mathew Bittleston

The water tanks are built near a spring at the top of the hill in Poly Canyon. This spring feeds Brizzolara Creek, the waters of which fed one of the creeks by the original mission in San Luis Obispo. The addition increased the water carrying capacity of the original concrete tank further up the hill.

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