--- slug: flowin-footbridge title: Flowin' Footbridge — Parametric low-carbon concrete pedestrian bridge in Moganshan, China hero_subtitle: A 20 m² bridge made of modular, prestressed low-carbon concrete blocks with steel tie-rods — featuring a fluid, parametrically generated geometry — for the tourist district of Deqing County. year: "2023" location: Moganshan Town, Deqing County (Zhejiang), China typology: Pedestrian bridge (Infrastructure) vertical_primary: 3D Printed Design vertical_primary_slug: 3d-printed-design vertical_secondary: 3D-Printed Design vertical_secondary_slug: 3d-printed-design badge_raw: 2023 · Moganshan Town, Deqing County (Zhejiang), China · Pedestrian bridge (Infrastructure) · Digital & Parametric Design + 3D Printed Design scheda: Location: Moganshan Town, Deqing County (Zhejiang Province), China Year: "2023" Client: Deqing County Cultural Tourism Development Group Co., Ltd. Typology: Pedestrian infrastructure — Footbridge for a tourist area Built-up area: 20 m² Project area: 30 m² Status: Unbuilt — a concept presented as a poster at the ACADIA/CAADRIA 2023 conference Lead Architects: Maurizio Barberio, Micaela Colella (Barberio Colella Architects) Design Team: Maurizio Barberio, Micaela Colella, Angelo Figliola Contributor: Zhenghui Chen Landscape, Structural, Environmental & MEP, Lighting: Barberio Colella Architects + Angelo Figliola Main materials: Low-carbon concrete (prefabricated modular blocks) + Steel (prestressing tie-rods and parapets) Design tools: Rhinoceros + Grasshopper (parametric modeling), Karamba3D (structural analysis integrated into Grasshopper), V-Ray (rendering) Publications: ACADIA/CAADRIA 2023 Poster (joint conference of the two leading associations for computational design in architecture) images: - filename: flowin-footbridge-rendering-01.jpg alt: Render of the Flowin Footbridge, a parametric bridge in China caption: "Exterior view of the pedestrian bridge: the continuous line emerges from the parametric structural simulation and blends into the hilly landscape of Moganshan." - filename: flowin-footbridge-top-view.jpg alt: Aerial view of the Flowin Footbridge with its fluid geometry caption: "The plan reveals the bridge’s fluid geometry: a curve that is not drawn but generated by the optimal distribution of pedestrian loads across the span." - filename: flowin-footbridge-rendering-02.jpg alt: Perspective rendering of the Moganshan pedestrian bridge caption: "Side view: the modular eco-concrete blocks are assembled in sequence using post-tensioned steel tie rods." - filename: flowin-footbridge-sections-progression.jpg alt: Variation in the cross-sections of the Karamba parametric bridge caption: The cross-section progression shows how the bridge cross-section varies continuously in accordance with the bending moments calculated using Karamba3D. - filename: flowin-footbridge-structural.jpg alt: Structural diagram of steel blocks and steel tie rods caption: "Structural scheme: eco-concrete blocks under compression, post-tensioned steel tie-rods under tension — a hybrid system that utilises both materials." - filename: flowin-footbridge-fabrication.jpg alt: The logic behind the fabrication of modular blocks caption: "The fabrication process: each block is a prefabricated component with a variable geometry, generated by the parametric model." - filename: flowin-footbridge-production-and-installation.jpg alt: Bridge installation process caption: "Construction and installation sequence: the blocks arrive at the site in the correct order, are assembled in sequence, and the post-tensioned steel tie rods secure the structure." faq_count: 6 related_slugs: - additive-stereotomy - urban-dunes - 3d-printed-mosque cta: title: Do you need to design a pedestrian infrastructure or a complex architectural feature? body: Whether you are developing a bridge, a footbridge, a shelter or a bespoke structural component — for the public or private sector, in Italy or abroad — we can work with you to explore the integration of parametric design, structural analysis and low-impact materials. BCA handles the design process from concept to fabrication files, liaising with manufacturers to ensure successful completion. button: Send us your brief microcopy: We’ll get back to you within 48 hours. No obligation. gallery_renders: - filename: flowin-footbridge-rendering-01.jpg alt: Render of the Flowin Footbridge, a parametric bridge in China caption: "Exterior view of the pedestrian bridge: the continuous line emerges from the parametric structural simulation and blends into the hilly landscape of Moganshan." - filename: flowin-footbridge-rendering-02.jpg alt: Perspective rendering of the Moganshan pedestrian bridge caption: "Side view: the modular eco-concrete blocks are assembled in sequence using post-tensioned steel tie rods." - filename: flowin-footbridge-rendering-03.jpg alt: Flowin Footbridge render – view from below the stream caption: "View from below the bridge: the eco-concrete arch structure spans the stream in the natural setting of Moganshan, with the joints between the blocks clearly visible." - filename: flowin-footbridge-top-view.jpg alt: Aerial view of the Flowin Footbridge with its fluid geometry caption: "The plan reveals the bridge’s fluid geometry: a curve that is not drawn but generated by the optimal distribution of pedestrian loads across the span." gallery_drawings: - filename: flowin-footbridge-general-plan.jpg alt: Flowin Footbridge general site plan – 1:200 caption: "The general site plan at 1:200: the bridge connects the two roads on either side of the canal, slotting into the residential fabric with elevations between +40.50 and +40.95 m." - filename: flowin-footbridge-plan.jpg alt: Flowin Footbridge plan – dimensions caption: "The plan view of the bridge with the main dimensions: 8.49 m span and 2.73 m clear width, with a fluid geometry that emerges from the optimal distribution of pedestrian loads." - filename: flowin-footbridge-section-aa.jpg alt: Flowin Footbridge longitudinal section A-A' caption: "Longitudinal section A-A': the eco-concrete block arch spans the canal with an 8 m span and 1.42 m rise, resting on the existing stone walls." - filename: flowin-footbridge-section-cc.jpg alt: Flowin Footbridge longitudinal section C-C' – post-tensioned tendons caption: "Longitudinal section C-C' with the post-tensioned steel tendons (red dashed lines): the slope of the walking surface is kept at 5%, ensuring accessibility." - filename: flowin-footbridge-section-bb-dd.jpg alt: Flowin Footbridge cross-sections B-B' and D-D' caption: "Cross-sections B-B' and D-D': the profile of the eco-concrete block varies depending on its position along the arch, with integrated steel railings and a dry-stone masonry foundation." - filename: flowin-footbridge-details.jpg alt: Flowin Footbridge construction detail – 1:10 voussoir caption: "Construction detail of the voussoir at 1:10: the section reveals the topologically optimised internal structure, with triangular openings that lighten the block while preserving structural strength." - filename: flowin-footbridge-sections-progression.jpg alt: Variation in the cross-sections of the Karamba parametric bridge caption: The cross-section progression shows how the bridge cross-section varies continuously in accordance with the bending moments calculated using Karamba3D. - filename: flowin-footbridge-structural.jpg alt: Structural diagram of steel blocks and steel tie rods caption: "Structural scheme: eco-concrete blocks under compression, post-tensioned steel tie-rods under tension — a hybrid system that utilises both materials." - filename: flowin-footbridge-fabrication.jpg alt: The logic behind the fabrication of modular blocks caption: "The fabrication process: each block is a prefabricated component with a variable geometry, generated by the parametric model." - filename: flowin-footbridge-production-and-installation.jpg alt: Bridge installation process caption: "Construction and installation sequence: the blocks arrive at the site in the correct order, are assembled in sequence, and the post-tensioned steel tie rods secure the structure." --- # Flowin' Footbridge — Parametric eco-concrete pedestrian bridge in Moganshan, China _A 20 m² pedestrian bridge made of modular, prestressed eco-concrete blocks with steel tie rods — a fluid, parametrically generated geometry for the tourist district of Deqing County._ **2023 · Moganshan Town, Deqing County (Zhejiang), China · Pedestrian bridge (Infrastructure) · Digital & Parametric Design + 3D Printed Design** --- ## A line flowing through the landscape Moganshan, nestled in the hills of Zhejiang province just a few hours from Hangzhou, is one of the best-known mountain tourist areas in eastern China: bamboo forests, historic colonial residences, a sense of place built on tranquillity and the landscape. The Deqing County Cultural Tourism Development Group commissioned a new pedestrian bridge integrate an experiential route into the fabric of the tourist district. The challenge was not only technical — supporting pedestrian traffic over a short span — but also one of identity: to design a contemporary structure that would engage with the landscape’s sensibility without reducing itself to a mere vernacular reference or an out-of-scale authorial gesture. Barberio Colella Architetti, with Angelo Figliola and collaborator Zhenghui Chen, developed the project entirely using a parametric workflow — Rhinoceros and Grasshopper for modelling, Karamba for integrated structural analysis. The bridge’s form is not drawn out in plan and then verified: it emerges from the simulation of loads and constraints, so that every curve and every section is the direct result of structural behaviour. The result is a fluid, ‘flowing’ line — hence the name Flowin’ Footbridge — which crosses the site without imposing rigid directions on the surrounding landscape. The construction system combines two materials with distinct roles. The deck and parapets are composed of modular blocks of eco-concrete: a low-carbon concrete that reduces CO₂ emissions compared to standard concrete thanks to the partial replacement of Portland cement with less energy-intensive binders and the use of recycled aggregates. The blocks are prefabricated with variable geometries — the sequence can be seen in the project’s Sections Progression — and are assembled in succession using post-tensioned steel tie rods that ensure the structural cohesion of the whole. The parapets, also made of steel, complete the formal composition and serve as a guardrail. The layering of discrete stone blocks and continuous steel tie rods is the principle on which BCA also worked in Hypar Gate (Troyes, 2016) and Additive Stereotomy: a contemporary stereotomic language, where the geometry is generated by an algorithm and translated into manufacturable modular components. The project is currently unbuilt: presented as a poster at the joint ACADIA/CAADRIA 2023 conference, Flowin’ Footbridge documents the state of the art of BCA’s research into the integration of parametric design, computational structural analysis and low-impact materials applied to small-scale public infrastructure. For the Chinese tourism and cultural client, the bridge is an identity asset; for research, it is a publishable case study on the reduction of the carbon footprint of pedestrian infrastructure when the geometry itself becomes a tool for structural optimisation. --- ## Image gallery ![Render Flowin Footbridge parametric bridge China](images/flowin-footbridge/flowin-footbridge-rendering-01.jpg) *Exterior view of the pedestrian bridge: the continuous line emerges from the parametric structural simulation and integrates into the hilly landscape of Moganshan.* ![Top view of the Flowin Footbridge with fluid geometry](images/flowin-footbridge/flowin-footbridge-top-view.jpg) *The plan reveals the bridge’s fluid geometry: a curve not drawn but generated by the optimal distribution of pedestrian loads across the span.* ![Perspective rendering of the Moganshan pedestrian bridge](images/flowin-footbridge/flowin-footbridge-rendering-02.jpg) *Perspective side view: the modular eco-concrete blocks are assembled in sequence thanks to post-tensioned steel tie-rods.* ![Variation of Karamba parametric bridge sections](images/flowin-footbridge/flowin-footbridge-sections-progression.jpg) *The progression of sections shows how the bridge section varies continuously according to the bending moments calculated with Karamba3D.* ![Structural diagram of blocks and steel tie rods](images/flowin-footbridge/flowin-footbridge-structural.jpg) *Structural diagram: eco-concrete blocks under compression, post-tensioned steel tie rods under tension — a hybrid system that utilises both materials.* ![Fabrication logic for modular blocks](images/flowin-footbridge/flowin-footbridge-fabrication.jpg) *The fabrication logic: each block is a prefabricated component with variable geometry, generated by the parametric model.* ![Production and installation sequence for the bridge](images/flowin-footbridge/flowin-footbridge-production-and-installation.jpg) *Production and installation sequence: the blocks arrive on site in order, are assembled in sequence, and the post-tensioned steel tie-rods complete the system.* --- ## Technical specifications - **Location:** Moganshan Town, Deqing County (Zhejiang Province), China - **Year:** 2023 - **Client:** Deqing County Cultural Tourism Development Group Co., Ltd. - **Typology:** Pedestrian infrastructure — Footbridge for a tourist area - **Built area:** 20 m² - **Site area:** 30 m² - **Status:** Unbuilt — concept presented as a poster at the ACADIA/CAADRIA 2023 conference - **Lead Architects:** Maurizio Barberio, Micaela Colella (Barberio Colella Architetti) - **Design Team:** Maurizio Barberio, Micaela Colella, Angelo Figliola - **Collaborator:** Zhenghui Chen - **Landscape, Structural, Environmental & MEP, Lighting:** Barberio Colella Architetti + Angelo Figliola - **Main materials:** Low-carbon concrete (prefabricated modular blocks) + Steel (tie-rods and parapets) - **Design tools:** Rhinoceros + Grasshopper (parametric modeling), Karamba3D (structural analysis integrated into Grasshopper), V-Ray (rendering) - **Publications:** ACADIA/CAADRIA 2023 poster (joint conference of the two leading associations for computational design in architecture) - **Primary BCA vertical:** Digital & Parametric Design - **Secondary BCA vertical:** 3D Printed Design (for the stereotomic logic of the modular blocks, in line with BCA research on Additive Stereotomy and Urban Dunes) --- ## How does one design a small-scale public infrastructure that is distinctive, sustainable and structurally honest? Small-scale pedestrian infrastructure — bridges, footbridges, viewing platforms — generally suffers from a dual shortcoming: either they are standardised catalogue products that ignore the context, or they are costly formal gestures that rely on inefficient structural solutions. In prestigious tourist areas such as Moganshan, the client’s brief is clear: a recognisable structure that becomes a stop on the experiential journey, yet is also environmentally sustainable and technically coherent. Flowin’ Footbridge demonstrates that parametric design is not an exercise in style but a tool for efficiency: the geometry arises from structural analysis, the modular blocks reduce fabrication waste, and the low-carbon concrete cuts down on embodied CO₂. --- ## Frequently Asked Questions ### What is low-carbon concrete and why is it relevant for public infrastructure? Low-carbon concrete is a family of concretes with low environmental impact produced by reducing the Portland cement content (the production of which accounts for around 8% of global CO₂ emissions) through the use of alternative binders — geopolymers, fly ash, blast furnace slag — and/or recycled aggregates. For a public infrastructure project such as the Flowin’ Footbridge, low-carbon concrete reduces the project’s carbon footprint without compromising the mechanical properties required to withstand pedestrian and environmental loads. This choice is consistent with the Chinese public-cultural client, which is increasingly attentive to ESG standards even at a local level. ### How does the pre-stressed block structure with steel tie rods work? The bridge structure combines modular eco-concrete blocks (highly resistant to compression) and steel tie rods (highly resistant to tension) in a hybrid system that exploits the properties of each material. The steel tie-rods run longitudinally through the sequence of blocks, are post-tensioned on site and generate internal compression that keeps the blocks in contact and prevents the joints from opening under load. It is an ancient principle — already applied in historic stereotomic vaults with wedges and tie-rods — updated here with contemporary tools for structural analysis and digital fabrication. ### Why was a parametric workflow (Rhino/Grasshopper/Karamba) chosen for a 20 m² bridge? For a small span, the complexity of the problem lies not in the scale but in the coherence between form, structure and fabrication. Karamba3D, a finite element structural analysis plugin integrated into Grasshopper, allows the design to be iterated in real time: every geometric modification is immediately verified in terms of loads and deformations. This workflow allows for a geometry that is not ‘sculpted’ and then verified, but generated directly from the static conditions. For a client in the tourism and cultural sector, the advantage is twofold: a structurally robust structure and an engineering guarantee that can be documented right from the concept phase. ### What makes Flowin’ Footbridge consistent with BCA’s research on stereotomy and digital fabrication? Since 2016, the Barberio Colella Architetti studio has been developing a line of research on digital stereotomy — the cutting and assembly of solid blocks using computational tools — which has generated projects such as Urban Dunes (a vault made of 3D-printed sand blocks, Abu Dhabi 2020) and Additive Stereotomy (a vaulted system of 3D-printed blocks, NYIT 2018). Flowin’ Footbridge applies the same principles on a different scale (pedestrian infrastructure) and with a different material (eco-concrete): modular blocks, parametric geometry, reversible assembly. It is a case study on the scalability of the contemporary stereotomy paradigm. ### How does one integrate new infrastructure into a natural tourist landscape such as Moganshan? Moganshan is one of the historic tourist districts of eastern China, characterised by bamboo forests, colonial residences and a landscape sensibility rooted in local culture. The design response of the Flowin’ Footbridge is formal subtraction: a fluid line, gradually varying sections, a neutral material palette — eco-concrete in its natural colour and the steel of the tie-rods and parapets. The bridge does not impose itself as a self-referential object but becomes an element of the route, perceived as a continuous surface rather than an isolated structure. The modularity of the blocks also allows for potential relocations or extensions without destructive demolition. ### What are ACADIA and CAADRIA, and why is a poster there a relevant credential? ACADIA (Association for Computer-Aided Design in Architecture) and CAADRIA (Computer-Aided Architectural Design Research in Asia) are the two leading academic associations in the field of computational design in architecture. Their conferences are the forums where the most rigorous research findings on parametric design, digital fabrication and algorithmic structural analysis are presented. The ACADIA/CAADRIA 2023 poster (the joint edition) is a peer-reviewed validation of the project’s methodological rigour: within the international B2B circuit of computational design, it is the kind of credential that distinguishes a practice with a proven research track record from one with only generalist design capabilities. --- ## Do you have a pedestrian infrastructure or a complex architectural component to design? Whether you are developing a bridge, a footbridge, a shelter or a custom structural component — public or private, in Italy or abroad — we can work together to explore the integration of parametric design, structural analysis and low-impact materials. BCA designs from concept to fabrication file, coordinating with manufacturers for production. **[Send your brief]** _Response within 48 hours. No obligation._ --- ## Related projects - **Additive Stereotomy** — Vaulted system using 3D-printed stereotomic blocks (presented at NYIT, Stereotomy 2.0) - **Urban Dunes** — Urban vault made of 3D-printed sand blocks in Abu Dhabi (Honorable Mention, Cool Abu Dhabi Challenge) - **3D Printed Mosque** — Mosque with 3D-printed vaults in Kuwait _Discover our approach to Digital & Parametric Design →_