Effects of Ground Failure on Buildings, Ports, and Industrial Facilities

Abstract

Soil liquefaction occurred at many sites during the 2010 Maule, Chile, earthquake, often leading to ground failure and lateral spreading. Of particular interest are the effects of liquefaction on built infrastructure. Several buildings were damaged significantly due to foundation movements resulting from liquefaction. Liquefaction-induced ground failure also displaced and distorted waterfront structures, which adversely impacted the operation of some of Chile's key port facilities. Important case histories that document the effects of ground failure on buildings, ports, and industrial facilities are presented in this paper.

Structural performance and associated lessons to be learned from world earthquakes in Nepal after 25 April 2015 (MW 7.8) Gorkha earthquake

“…Due to continuous seismic activities in the region, Chile is being suffered by many strong to large earthquakes; beside this Chilean practices in terms of aseismic design and ductile detailing have undergirded the downscaled damage statistics of casualties. This earthquake hit across the Chilean cost for around 600 km and structural damage was attributed to site effects, basin effects, vibration resonance, ground failure, and causes in affected regions (details are reported by [5,11,60]). …”

“…Structural performance ▪ Horizontal reinforcement through infill masonry units was not provided so out of plane as well as in plane failures were prevalent ▪ Commonly beams were absent in structures leading to load diaphragm discontinuity and improper load distribution and propagation system was very frequent ▪ Smaller and weaker bricks with large voids were used as construction materials that were unable to sustain the superimposed load and added seismic forces ▪ Performance of timber structures was satisfactory and sustained the earthquake even most of the RC buildings were collapsed in affected areas Chile 2010 [25]; [5]; [11]; [60] ▪ Vast majority of medium to high rise structures were damaged due to possible vibration resonance and also due to structural as well as design and detailing deficiencies ▪ Chilean code has close acquaintance with UBC-97, however vertical and horizontal irregularities were not checked well and such irregularities led structural damage primarily in columns ▪ After the 1985 earthquake, the transverse bar spacing was not made so close considering the good performance scenario of largely spaced transverse bars, such large spacing of transverse reinforcement caused buckling on structural components. As the earthquake motion characteristics were different than that of 1985 earthquake, this factor aggravated the performance of structures in case of largely spaced transverse bars ▪ Buildings repaired after the damage during 1985 earthquake were seriously damaged and damage concentration was in the buildings with 10-26 storeys ▪ Most of the damage was concentrated in poorly designed and detailed recent constructions of that time ▪ Buildings with open ground storey used for parking sustained damage due to soft storey mechanism ▪ Buildings designed as per ACI guidelines were safer than those buildings designed using local code due to assurance of proper consideration of seismic forces ▪ Damage on coupling beams used above doorways was occurred due to largely spaced and small diameter hoops ▪ Doors were jammed due to lack of permanent offsets in the walls due to lack of coupling element and the slab itself worked as coupling element ▪ Spalled cover over lap slices was observed in the concrete compromised with proper batching and mixing ▪ Damage was also caused due to highly irregular wall layout -this damage resulted the collapse of structures ▪ Tension failure on transverse walls and decreased wall length on the first storey was occurred ▪ Scouring of shallow foundation caused several structures to slide or rock ▪ Considerable damage was observed on glazing, ceilings, fire sprinkler systems, piping systems, elevators, partitions, air handling units and cable trays due to improper anchorage and lack of confinement and connections ▪ No proper enforcement were functional in terms of anchorage consideration of non-structural elements was prevalent in Chilean code so non-structural damages were common, like 62% of 132 damaged hospitals consisted non-structural damage only Gorkha (Nepal) 2015 ▪ Minor to moderate damage occurred in 3 to 6 storied moment resisting frame buildings; however severe damage was more localized ▪ Majority of damaged RC buildings were poorly designed structures undergone with incremental construction, without any further seismic as well as gravity load considerations ▪ Soft storey collapse and brittle failure of structures were observed in some locations due to strong beam weak column mechanism (Fig.…”

Seismic risk at urban scale: the role of site response analysis

“…As demonstrated by recent earthquakes, local site response plays a crucial role in the extent and nature of the damage patterns observed for different structural systems at urban scale (Maugeri et al, 2011;Assimaki et al, 2012;Sextos et al, 2018). Physical damage is further exacerbated if also ground failures (e.g., landslides and liquefaction) occur (Esposito et al, 2000;Bray et al, 2012;Franke et al, 2018). It is therefore very important to take into account site effects in the seismic risk assessment at urban level.…”

Pérdidas de vidas, viviendas, infraestructura y embarcaciones por el tsunami del 27 de Febrero de 2010 en la costa central de Chile

“…Winckler et al (2011) identifican diversos tipos de daños, sin efectuar una cuantificación. Olsen et al (2012) y Robertson et al (2012) analizan los daños por el tsunami en edificios e infraestructura; las instalaciones industriales son abordadas por Zareian et al (2012); mientras los daños en puertos son estudiados por Zareian et al (2012), Brunet et al (2012) y Bray et al (2012. Robertson et al (2012) analiza los efectos sobre líneas de vida, reconstrucción y recuperación.…”