Slope failure in Lincoln community was triggered by heavy rainfalls during Typhoon Winnie attacked Taiwan on 18 August 1997. The slope failure killed 28 persons and destroyed 80 houses. This disaster attracted the public attention on the safty problem of slopeland area. This paper presents the emergency respsonse during rescue mission and the treatments to prevent the secondary disaster might be induced by the next typhoon.
According to geological survey and evaluation results of the Linken County Neighborhood（hereinafter refers to as “Neighborhood”）, it is studied and judged that the geological conditions of the Neighborhood belongs to geological sensitive area with dip slope, furthermore, the geotechnical design and planing of this County did not aim directly at the geotechnical conditions. The risky geotechnical treatment such as cut slopes and filled in the valley were adopted which caused the collapse in dip slope area, and differential settlement and unstable retaining wall in the filled area also. So, that the reinforcement design by professional engineers and emergency treatment should be adopted as soon as possible.
This paper presents the investigation methods and results of the causes for Lincoln residence’s disaster. The investigation includes the site inspection, information collection, anchor testing, geological exploration, and slope stability analysis. According to the investigation, the Lincoln residence’s disaster induced by a dip slope failure. The toe of the dip slope was excavated. The design and construction of the retaining structure and anchoring system was inappropriate. Due to Wenny Typhoon’s heavy rainfall, ground water pressure increased and resulted in the slope failure.
The compound of many adverse factors and wrong doings has caused the landslide disaster,though basically avoidable, at the north part of Lincoln Community. Paired with test results, advanced investigation indicates that the disastrous landslide relates directly to some inadequate strength parameters and deficient assumptions for groundwater level. This article discusses the major causes of the calamitous landslide,hoping to evoke more retrospection and alertness in the engineering field. The authors endeavor to prevent similar wrong doings in the future. The remedy proposal stands for a personal view of the authors; however, it may also serve as a reverence measure and a discussion object for the public.
In recent years, disasters in slopeland communities have repeatedly occurred in Taiwan. Despite these accidents, the residents of Taiwan have ignored the warning of these accidents. Typhoon Winnie, August 18,1997, trigged disastrous landslide at the Lincoln Residential Community, The Catastrophe at the Lincoln Residential Community has finally focused the national attention on the problematic slopeland housing developments of Taiwan. After safety inspections of the hillside developments, the county governments have concluded that the main source of the safety problem lies within improper soil and water conservation. The goal of this aftermath report, on the soil and water conservation safety assessment of the Lincoln Residential Community, is to invoke a national awareness on the importance of proper soil and water conservation.
The Lincoln Residential Community is situated in the township of Shijr, Taipei. This site was originally a valley. After heavy earthwork, the original valley waterway was replaced by a system of culverts to convey the water to Pei-kung Creek. This safety assessment investigates the cause of the disaster by focusing on the soil and water conservation that was done on the Lincoln housing site. It also further investigates the possibility of future disaster at the Lincoln site through the landslide analysis and data collected from on site analysis (vegetation, slopeland stabilization, drainage systems, soil erosion assessment, etc.)
The intense rainfall associated with Typhoon Winny, passing through northern Taiwan in August 18, 1997, triggered a fatal rock slide disaster in Lincoln residence, Taipei County. The slope failure destroyed and damaged 100 houses located in downslope area. 28 lives were killed and 50 injured by the collapsed buildings. The failed slope is comprised of the Miocene Shiti Formation, which is mainly composed of alternation of the sandstone and shale with the bedding plane dipping 30 degree downslope. The planar failure occurred along bedding plane and a huge slab of rock with 150m (Length) X 58m (Width) X 10m (Thickness) in size moved downslope rapidly. The moved slab was also separated into two halves by an extensional joint trending perpendicular to the strike of bedding plane during the movement. The main causalities of the catastrophe can be mainly attributed to the improper design of the housing project. First of all, the designers ignored the geological conditions of the unstable dip-slope consisting of bedded sedimentary rocks with weak bedding planes. The supporting material had been unwisely removed from the toe of the slope during construction at the base of the slope. After the intense rainfall, the high water pressure accumulated behind the retaining wall and decreased the friction of the bedding plane. The strength of retaining wall and anchors been set on the slope are insufficient to retain the unstable block from downslope movement.
In this Article the damage conditions and vertical inclination of the buildings at Lincoln Village, and the seismic resistant capacities of building structure after seismic risk will be described. Due to the safety of building structure closely related to the foundation by the different water levels, by induction of earthquake input and by the different underground soil profiles. Finally, based upon the damage conditions of the building structure, geologic survey and geotectonic analysis of soil profiles, It can be concluded that the degree of safety of building structures after the disaster is closely related to the type of foundation used and the ductility of structure themselves.
This article discusses the geotechnical engineering concerns in the hilly land development, in light of the Lincoln Community case. The local geological conditions at Lincoln Community may be characterized by dip sloping and some local thick fill soils. Major engineering concerns include settlement, stability of soil layer and retaining structures, lateral pressure on buildings associated with differential elevations, fill soil erosion, and groundwater seepage along the valley. In addition, other issues are also crucial in land development on slopes, such as the difficulty in establishing breakwater and drainage system at the upper valley because of land ownership, and the slope instability caused by further land development at the lower slope. Appropriate development plan and detailed construction management are pivotal to successful land development on slopes.