by Dr. James Mwangi, Simpson Strong-Tie Engineering Excellence Fellow 2017-18 Arriving on the other side of the Pacific The journey to Padang, Indonesia started on August 3rd, 2017 in San Francisco, California with connections in Manila, Philippines and Jakarta, Indonesia. I arrived exhausted but excited in Padang on August 5th after almost 24 hours in the air. Padang is the provincial capital of West Sumatra and lies just south of the equator. The high temperatures are usually in the low 80’s, with lows hovering around the mid-70’s (Fahrenheit). I arrived in what is said to be “dry season” (May-September), although the high humidity and rain do not coincide with my experience of dry seasons elsewhere. I imagine the wet season (October ‐ April) is like living in a swimming pool. Padang’s old town lies in the low land, designated a … Read More
Women are leading the way towards the recovery of earthquake-affected communities in Nepal. Nearly 750,000 buildings were damaged or destroyed in the earthquakes in early 2015, leaving families in temporary shelters and students learning in makeshift school buildings. Rebuilding this infrastructure so that it does not collapse again in a future earthquake takes more than just bricks and money. Access to professional engineers and trained builders, along with other information on safe building techniques, are all crucial to rebuilding safer houses and schools. So, how do people in rural areas – often with unreliable transportation and communication systems – gain access to information and trained professionals to help rebuild their houses and schools? Technology is changing the way people can access these resources, and women are emerging as leaders in this field as well. Khusbhu Gupta is a Computer Engineer and … Read More
From February 23 to February 25, 2017, Carl and Linnel from our engineering team in the Philippines performed post-earthquake reconnaissance following the 6.7 earthquake in Surigao Del Norte, on the north side of the island Mindinao. The team investigated and documented the response of rural school buildings and informal urban housing in the area, which will help inform our retrofit efforts in Manila and further our understanding of the seismic vulnerability of school buildings. The highest concentration of damaged housing exists in Surigao City, and San Francisco has experienced the most significant damage to schools. Unfortunately, San Francisco is inaccessible due to collapsed bridges and damaged roadways, and the team’s efforts have therefore been focused in Surigao City. Surigao City is a moderately dense city with a population of about 160,000 people. The team flew into Butuan on Thursday, about 4 … Read More
On May 3rd, we went with Gen. Ruiz and Ing. Flores into the barricaded area of Manta, the neighborhood of Tarqui. This area had the most damage and was a mix of large to small commercial buildings and hotels, plus multi family and single family houses (some mixed use). Many of the small and medium sized buildings that had collapsed were already demolished and some were being taken down while we were there. There were buildings with very different performance on the same block and the reason for the difference in performance was not obvious. Additional investigation is needed to see really why some had collapsed and others did not. There were several green-tagged residential buildings in the area – particularly along one street. Though one of the homeowners there was telling us that they didn’t know if … Read More
After Canoa, we next headed north to Jama, another coastal town. In Jama we selected a street in town and compared the building type and performance of each, one-by-one. There were 7 houses, some with commercial space below. Six houses were wood framed, 2-stories, and one was reinforced concrete, 3-stories. Of the wood framed, 5 had masonry infill at the ground floor and 1 had bamboo lath with plaster overlay at the ground floor. Four had wood only walls at the upper level while two had mixed wood and masonry infill walls at the upper level. In general of the wood-framed buildings, we saw the most damage (wall and partial roof collapse) in the upper levels of buildings where wood and masonry infill walls were mixed. This is probably because the wood walls were not sufficient to resist the larger … Read More
This morning we met with Ing. Hermel Flores, owner of Hermel Flores Construcciones and former chair of the Ecuatorian Chamber of Construction, and General Florencio Ruiz Prado, Director of Citizen Security for Manta, in Manta. We discussed our activities, the situation and the presentation they coordinated for us to give on Tuesday and Wednesday, in Manta and Portoviejo, respectively. Ing. Flores traveled with us next up north towards the epicenter. The coast of Ecuador is in the highest seismic zone of the country. There are RENAC sensors located up and down the coast which recoded the accelerations in the recent earthquake. The records from these sensors are being retrieved and processed. We’re looking forward to the report on those coming available soon to see how they compare with what we observed along the way. We stopped in Canoa and checked … Read More
May 1st was our first full day in Ecuador, after landing in Guayaquil on April 30. Our team has three members: Traveling from our Bogota office there is Juan Caballero, architect and Director of Programs and Partnerships for Latin American, and Walter Cano, structural engineer and Project Engineer for Colombia. From the U.S./headquarters there is Lizzie Blaisdell, structural engineer and Director of Engineering. In Guayaquil, we saw little evidence of an earthquake. According to the preliminary report on the Instituto Geofisico website (http://www.igepn.edu.ec/) a strong motion sensor near Guayaquil, “AGYE” experienced a maximum ground acceleration of 23.04 cm/s2 (approx. 2%g) while another just east of the area, “AMIL” recorded a maximum acceleration of 51.04 cm/s2 (approx. 5%g). As a point of comparison, the new Norma Ecuatoriana de la Construccion (Ecuadorian Construction Code) considers the seismic zone factor, Z, to be 0.4. For … Read More
Look at the top of the wall. The decision to lay the top course of blocks on its side for extra ventilation was an extremely bad one, making it so the seismic load in the roof slab has no competent load path to the shear wall below. In the retrofit evaluation our engineers give this wall no credit for seismic resistance–it will have to be fixed.