Landslide Festival

Nantou, Taiwan / Landscape and Material Development

Taiwan is an island with mountain chains in the center, and there are lots of upland settlements, which are mostly remote, fragile and sensitive to change of environment. Special conditions of these villages are not only limits but also hints that special materials, tools, and methods should be used.

Shenmu (Sacred-Tree) Village, a Hakka village surrounded by mountains in Nantou, was formed to support the camphor industry during the Japanese occupation period. In Shenmu, landslides occur every rainy season. To elude the landslides, the villagers have adopted a circulating nomadic life style based on agriculture, religious event and climate.

Raw lacquer is a common forest resource in Taiwan, but forgotten along with the declination of forestry. It is mainly used to produce coating material. In some researches, similar materials were proved to be effective stabilizer of rammed earth, and that gave me a hint to test raw lacquer as stabilizer for durability and structural strength. All the tests were following NZS 4298:1998.

In durability test, unstabilized specimens were eroded obviously and water permeated the specimens. However specimens with raw lacquer showed perfect durability with dense membrane formed on the surface of specimens. Water just slid along the surface. No erosion and penetration was detected.

In compression test, pure rammed-earth specimens have similar compression strength under 0.2N/mm 2 . Dark-brown lac-stabilized specimens can be about 10 times stronger than unstabilized ones in compression strength. Some specimens with specific proportion are above 2N/mm 2 , approaching the strength of cement-stabilized ones (Daniela Ciancio, et al. 2011) and onethird stronger than rammed-earth with other natural stabilizer like seaweed biopolymer (C. Dove, 2014). All the specimens with more than 2.5% raw lacquer reached requirement of earth construction material, 1.3N/mm 2 , in NZS4298. Among all specimens, those with 5% raw lacquer and 10% aggregate are the strongest. Besides compression strength, raw lacquer increases the ductility of rammed earth, which means larger strain is allowed before failure.

To Shenmu, landslide could be a big threat but also an opportunity. Landslides are plentiful supply of gravels and earth, which can be used to restore the damages and construct the renewable protection for the next landslide. Rammed-earth stabilized with raw lacquer, which is accessable around the village, was adopted to organize the materials from landslides and agriculture by-products for the restoration and new constructing, and this new type rammed-earth material had been proved to be stronger, waterproof, and environmentally friendly. I seperated the environment into several layers, stratum, infrastructure and buildings, sediments and temporary constructions, and human activities, from stable to flexible. This project reveals the individual specificity and interaction of these layers through earth-ramming in landscape scale. With anchors in layer of infrastructure and buildings, different steps of earthramming, like sieving, ramming, and layering, are accomplished in different parts of the settlement. All the infrastructure and constructing with rammedearth aim at guiding and utilizing the landslides instead of resisting. "Ramator" reformed from excavator is the main tool to ram the layers together with special bucket.

There are two spiritual spaces in Shenmu, Sacred-Tree Temple and Earth Temple.

Earth Temple locates at the intersection of three rivers where also landslides gather. As the religious center of village, traditional events are held here every year. Topography, water/earth flow and excavator dimensions are followed to design a series of earth collecting and ramming infrastructure. When landslides, the flows of earth and stones are guided through the uphill aqueduct, decelerated, filtered, and precipitated for further use.

Sacred-Tree Temple between village and hunter route is the origin of the village, and the ablution place at the beginning of the forest track. It was redesigned as a shelter to protect Tree and people in forest, using rammed earth brick from Earth Temple and gabion.

Time loop of agriculture, religion, landslides and restoration in the village are integrated through the programs of spiritual spaces. In summer, landslides and restoration keep changing the appearance of the village. After each landslide huge rammed earth cubes stabilized with raw lacquer are dried in the court of Earth Temple and form a temporary geological park simulating the time slice of landslide. The cubes are later used to build new sand blocking dam and repair Sacred-Tree Temple. In autumn, earth cubes are piled up to form shelter and outdoor theater with bamboo and canvas for the grand harvest festival. God parade, sacrifice, catering, Chinese opera, different events are hold around the village. In winter, villagers pray in Sacred-Tree Temple and then go hunting and gathering ai-yu and raw lacquer in forest. Cube shelter in front of Earth Temple is used as ai-yu processing hut. In spring, cube of the shelter are recycled and mixed with fiber of ai-yu to construct diversion wall.

Two opposite spaces are reorganized as a system of landslides control and utilization, and simultaneously their differences are emphasized by comparison of space arrangement, material and constructing method. Cohesive and dispersive, stagnated and flowing, plan-oriented and sectionoriented, constructing and deconstructing, void and solid, conflict and harmony, two spiritual spaces are telling the story of Shenmu village.

The new spiritual spaces design provides a safe and initiative system to face and utilize the threat from nature. They also "ram" the hearts of villagers together.