Wenchuan Reconnaissance Report #3
Philip Yong & Jiashun Yu, 5 Nov 2008
On Day 2, the NZSEE team travelled from Chengdu and headed north towards the second epicentre in the township of Beichuan. We travelled on an expressway for most of the way, and passed through a number of sizeable towns (cities by NZ standard), including Deyang and Mianyang. There are a number of medium to high rise buildings, power pylons, communication towers etc. in these towns, all of which appear to have performed quite satisfactorily.
We note a trend of progressively more obvious structural damage, as we head north west on the road towards Beichuan, passing through the Anxian township. There are serious damages and at times total collapse of buildings in the villages, especially the older unreinforced masonry type structures, as we get closer to Beichuan. There were also many huge earthquake induced landslides on the slopes on the hills, with very large boulders amongst the debris.
Beichuan is now closed to the public, but we were able to observe from a high point perched on hill at the west side of valley, looking into the township. The township of Beichuan is destroyed and now abandoned with many of the deaths still buried in the rubbles. Beichuan suffered from the following major events:
Earthquake induced landslides on both the eastern and western slopes on the 12 May 2008Flooding due to release of water from a quake lake upstream Heavy rain resulted in a major debris flow that buried a large part of the town on the 24 Sept 2008.
We next went through the village outside the gate entry to Beichuan, and observed the totally collapsed blocks of the local high school due to May 12 earthquake. There were also a number of buildings that remain intact, we believe due to better materials and structural form. The debris flow from landslides on Sept 24, due to heavy rainfall, had resulted in a number of the school buildings and facilities buried.
We noted large areas of temporary houses and schools in light weight materials in the area not far from Beichuan, equally there are still a lot of tents around the disaster area. Life does go on in these clusters of temporary housing blocks, with banks, medical services amongst them. A lot of re-construction of houses is going on, using brick masonry, sometimes on the same spot of the collapsed houses.
We had a close look at a concrete arch bridge with concrete deck, within 20 km away from Beichuan, that suffered some minor damage.
A sample of the pictures from today’s site visits are appended.
Beichuan township: destroyed by earthquake and landslides, flood from quake-lake upstream, and debris flow caused by heavy rain.
Beichuan: massive landslide at the eastern side of the valley
Source of debris flow into Beichuan
Beichuan entry gate area: Boulders that came down in the earthquake
Massive landslide just outside Beichuan township
Slip along the road from Anxian to Beichuan
A secondary school building near entry gate to Beichuan: minor damage
A totally collapsed school building near entry gate to Beichuan
Debris flow against the school canteen building
Debris flow inside the school canteen building
Anxian: an undamaged building
Anxian: pounding between buildings
Temporary housing units close to Beichuan
An arch bridge on the road not far from Beichuan: very minor damage
Re-construction is happening, in traditional materials
On Day 2, we saw massive land effects due to earthquake that destroyed an entire township. The rainy season following further added to this already an impossibly serious problem.
We saw a lot of temporary housing in communities and the rebuilding is starting to happen.
Philip Yong & Jiashun Yu