Boulder Park, a 13,000m² community park in Ji'nan, incorporates large boulders - a natural material symbolizing eternity - as the central design element. These boulders integrate with the park's functional and experiential activities. Boulders placed over a sandpit are transformed into climbing and resting play structures; stones in the shallow creek can become part of the water play installation. Additionally, a massive rock cave adventure space is constructed using advanced 3D-printed concrete technology.

Designed by XISUI Design, it integrates children's play areas with water features and natural landscapes, offering a space for intergenerational interaction and community engagement.

Design background

Boulder Park occupies the central area of Yunwan Garden in Ji'nan. This 13,000m² space functions as a comprehensive community park combining a children’s playground, shallow stream water activities, family interaction, and leisure. According to the style characteristics and functionality, the park is divided into multiple areas:

• All-Age Boulder Playground
• Water Garden
• Forest Garden
• Stone Garden
• Flower Garden

XISUI Design was responsible for the design of the children's activity areas, including the All-Age Boulder Playground, Water Garden, and Forest Garden.

All-Age Boulder Playground and Forest Garden

In terms of interactive experiences, the All-Age Boulder Playground and Forest Garden feature a variety of children's activity facilities such as swings, slides, seesaws, trampolines, rocking horses, merry-go-rounds, climbing tunnels, speaking tubes, climbing ropes, and more. These facilities are integrated into the natural landscape, formed by large stones and concrete caves. The design provides children with fun, while also helping them develop limb strength. Beyond physical growth, these activities promote the development of the brain's ability to recognize nature, balance, and other essential skills.

Water Garden

Located to the west of the All-Age Boulder Playground, the Water Garden features an outdoor water play area with babbling shallow streams, blending naturally into the surrounding landscape. The design team at XISUI Design focused on creating interactive water play experiences suitable for all ages. Children can engage with fountains, feel the flow of water, and explore jumping springs, winding creeks, and a water turntable - each designed to engage children and stimulate curiosity. Water pumps and pressure devices add to the experience, providing opportunities for exploration and learning. This interactive environment fosters a connection between children and nature, allowing them to engage with water and feel its gentle power firsthand.

Main installations

The standout feature of the park’s installations is its use of advanced construction technology - 3D concrete printing. This additive manufacturing method produces monolithic structures with complex, free-form curved shapes based on digital models. Such shapes are challenging to achieve through traditional formwork.

3D concrete printing uses a computer-controlled robotic arm that precisely extrudes liquid or semi-solid concrete, which then solidifies, building the structure layer by layer. The essence combines digital design and material science, offering unprecedented freedom and complexity in spatial design and construction. The resulting layered rock textures create distinctive surface textures that visually resemble the natural rock formations of boulders and caves. Moreover, its advantage of forming organic shapes at once improves both the spatial accuracy and user experience.

• ​​3D concrete printing monolithic molding​​
  Digitally-controlled 3D printing enables monolithic molding of complex organic shapes. This not only significantly improves shape accuracy, effectively avoiding inevitable errors in conventional craftsmanship, but also reduces reliance on manual skills, showcasing the close fusion of technology and art.
  
  
• Layered canyon
  The unique layered rock texture of the 3D printing technique complements the surrounding natural stone landscape, meeting current functional needs while maintaining an atmosphere of exploration and adventure. Children playing among the "boulders" seem to be traversing real canyons. Meanwhile, the subtle curves of the surface naturally create steps, handrails, slides, and seating elements, harmonizing function with the form of the installation.
  
  
• Safety and fun
  Safety and enjoyment are paramount in children's play areas. All 3D-printed landscape installations are designed with smooth edges and rounded corners to ensure that there are no sharp or hazardous points that could cause injuries. The cave-like scenes, with slides, tunnels, and speaking tubes, combine the garden environment with children's play activities in terms of form and function.

“Landscape structures and installations are often small in scale, with low load requirements and simple, clear functional needs. In the application of 3D-printed concrete technology, compared to architecture, landscape projects may have even more diverse usage scenarios," explains Hu Yihao, Lead Designer. "Although the current 3D concrete materials still face a series of challenges, such as uneven stress distribution and relatively simple reinforcement methods, the 3D printing materials used in Boulder Park have an average strength of 50MPA, surpassing the traditional C40 concrete strength standard."

"This technical specification is more than sufficient to meet the structural needs of most landscape installations and structures," adds Mr. Yihao. "In landscape projects, outdoor durability, the ability to achieve organic shapes, ease of construction and installation, and cost savings in labor are the primary considerations. 3D printing technology, with its significant advantages in these aspects, has become an ideal choice for this purpose.”

Conclusion

The park shows how new technology - 3D concrete printing - can enhance public spaces, while respecting local culture and the environment. By integrating 3D-printed concrete elements with natural features, it offers a space for play, exploration, and connection with nature. This project exemplifies how 3D-printed concrete elements harmonize with their surroundings, providing both functional and aesthetic value to the community.