Abstract

Stockaded villages of the Qiang nationality that are made up of watchtowers and watch-houses are an important part of its cultural heritage. The earliest documentary records of its blockhouse-styled construction can be found in Biography of the Ethnic Minority Groups in Southwest China of History of Eastern Han. In 2006, watchtowers and stockaded villages of the Qiang nationality was placed in the preparatory declaration list of world cultural heritage in China and became a minority architectural heritage that is of potential value for world cultural heritage. The Wenchuan earthquake, which happened on May 12th, 2008, caused severe damage to settlements of the Qiangs in the upper reaches of Min River, including the “Tangping Qiang village, ” which plays a prominent role in Qiang stockaded villages. In conserving this important architectural heritage, we observe the idea “everything for heritage value”. We discuss and draw up a series of salvage conservation countermeasures and research for antiseimatic key technology during post-earthquake reconstruction period of Tibetan and Qiang settlement engineering projects, including six engineering principles on priority of structure rescue, heritage value, former address maintenance, traditional way of use, protection against and mitigation of earthquake disasters, and spot cleaning and separating. We draw up three rules in engineering strategy, namely: (1) we should follow ultimate orientation of heritage value protection in rescue, maintenance, and protection engineering, (2) degrees of priority of engineering measures should be differentiated according to the situation of the disaster and residential situations of stockaded villages and, (3) we should keep local smiths and conventional art as the base, and modern technology as a supplement in rescue, maintenance, and protection engineering.

Abstract

Some important infrastructures like roads, railway tracks or dams were constructed in places threatened by natural hazards. With the purpose of preserving these infrastructures from landslides and rock-falls, different containment systems are installed, and one of the most popular are the
flexible metallic fences.

The development of full-scale laboratory tests to evaluate the behaviour of flexible metallic fences is unfunctional, accounting to the huge magnitude of the event. On the other hand, small-scale testing may lead to inaccurate results, due to the distortion in the contours (e.g. anchors of the metallic fences). These problems in laboratory testing have led to the popularization of the use of numerical methods.

In this study, the bonded Discrete Element Method (DEM) is used for the analysis of the behaviour of flexible metallic fences for rockfall protection. The bonded DEM is a modification of the classical DEM which assumes that bonds exist between particles, resisting their separation. In this case, the net cables are represented using rigid spheres joined by bond elements that are deformed according to an elasto-plastic law.

Calculations were carried out using the DEMPack program, a specific software developed in CIMNE for modelling with the bonded DEM. This software allows considering the inter-action between discrete and finite elements, which can be useful to represent the boundaries of the domain, such as the surface of the slope.

The code is firstly validated reproducing benchmark tests available in the literature. Finally, full-scale tests are computed in order to evaluate the energy dissipation capacity of the fence during a rockfall event.