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Equipment
Published in Len Holm, John E. Schaufelberger, Construction Cost Estimating, 2021
Len Holm, John E. Schaufelberger
Concrete wall panels for a tilt-up structure typically are cast on a concrete floor slab. When properly cured, a crane is used to hoist the panels into place. Once elevated, the panels must be braced and connected with adjoining panels. Because the safe lifting capacity of a crane is reduced as the boom is lowered, the crane may need to be relocated multiple times around the walls being constructed with the tilt-up panels. Mobile cranes with hydraulic booms are often used to set the concrete panels. Since the crane is to be used for a single purpose, its cost would be included in the direct cost of wall erection. To lift the pre-cast panels, the GC would issue a hoisting subcontract to a crane company for the equipment and labor needed to operate the crane.
Walls
Published in Syed Mehdi Ashraf, Practical Design of Reinforced Concrete Buildings, 2017
Other varieties of walls include precast concrete walls and tilt-up concrete walls. The concrete of precast concrete walls is cast at the factory, and they are shipped to the construction site, installed in place, and connected to the concrete frames or the diaphragms. The concrete of the tilt-up walls is cast at ground of the construction site and the walls are tilted up to install them at place and connect them to the concrete frames or diaphragms.
Geotechnical Reconnaissance of the 2016 ML6.6 Meinong Earthquake in Taiwan
Published in Journal of Earthquake Engineering, 2018
Chi-Chin Tsai, Shang-Yi Hsu, Kuo-Lung Wang, Hsuan-Chih Yang, Wei-Kuang Chang, Chia-Han Chen, Yu-Wei Hwang
The liquefaction area was between Wenhe St. and Wenxiang St., with a total area of 5,000 m2. The GF distribution is shown in Fig. 12. The neighborhood experienced sand ejection along the perimeter of the buildings and minor-to-moderate differential settlement between the pavement and the edge of the building (a few cm up to 10 cm). The most severe damage occurred in the alley between Nos. 88 and 84 of Wenhe St., where the differential settlement was up to 20 cm. Only one slender building (No. 84-6, Wenhe St.) suffered significant tilt up to 4° toward Wenxiang St. Similar to the observation at other liquefaction areas, this tilted building is an isolated single house. The other structures that exhibited settlement were townhouses attached to adjacent buildings. A recently re-constructed single house located 10 m away from the tilted structure exhibited neither settlement nor tilt. This phenomenon was because the building was established on a mat foundation with a 40 cm bottom slab 4–5 m below the grade. This type of foundation design compensated for the structure load and transferred the load to deeper non-liquefied layer. These observations also indicated that the liquefaction in this area was quite shallow.
Review of Seismic Risk Mitigation Policies in Earthquake-Prone Countries: Lessons for Earthquake Resilience in the United States
Published in Journal of Earthquake Engineering, 2022
Yating Zhang, Juan F. Fung, Katherine J. Johnson, Siamak Sattar
In California, many non-ductile concrete buildings were constructed before the 1976 Uniform Building Code came out, which prevented insufficient steel inside concrete columns and beams. However, the 1994 Northridge Earthquake caused severe damage to apartment buildings and hospitals that were designed even after the 1976 code. Inadequate strength in the anchorage system of the wall to the roof and floor diaphragm was found to be the major reason. Thus, new provisions were introduced into the 1997 Uniform Building Code to increase wall anchor design forces in concrete tilt-up buildings, accompanied by stricter detailing and inspection requirements.
Design of virtual laneway infrastructure: community activation through augmented reality in underutilized spaces in cities pressured to densify
Published in Journal of Urban Design, 2023
Emil Jonescu, Eric Choh, Ahmed Hammad, Khoa Do
This study undertook a criteria-based analysis through observation and measurement, assessing 34 laneways within the city of Perth’s CBD. Of the 34, however, physical field study measurements were performed on the nine municipal-owned or part-owned laneways identified as potential case study locations. At the time of the study, the remaining 25 laneways were precluded from potential selection due to restricted use ‘implied rights’ to its use and development zoning and guidelines (Western Australian Planning Commission (WAPC). Parameters included ownership, which was used as a pre-selection criterion (Table 1). A further nine parameters were analysed and further outlined in Table 2, including: [1] proximity to residential residence, [2] proximity to mass transit public transport (central station), [3] prospect for linking critical nodes and infrastructure, [4] length, [5] width, [6] average width, [7] vertical brickwork courses, [8] height, and [9] average approximate effective canvas area (ECAm2). Measurements were undertaken over a 3-month period in 2018 (September – November). Physical site measurements of length, width, and height were taken to determine physical proportions and to calculate the approximate effective canvass area. Laneways with limited width uniformity were measured across multiple points to determine an average overall width. Priority for determining ‘potential’ was considered on basis of the preponderant width in each instance. The canvas area was determined by multiplying the average façade length by the average façade height of buildings in each lane, multiplied by two (2) accounting for two façades. No deduction was made for openings and windows. Building heights were determined three ways: [1] by counting the number of standard brick courses (c) per building (standard bricks measuring 76 mm × 230 mm were used across most lanes). A standardized brick coursing chart (Brick 2020) was used to determine the building height by the brick courses counted (allowing for reasonable tolerance). Coursing heights was cross-checked with Google Earth Pro (Google Earth n.d.). [2] Laneways with mixed buildings construction methods including pre-cast construction, tilt-up, glass and steel, or no visible brick coursing – heights were determined through the use of Google Earth Pro (Google Earth n.d.) measurement tools and no coursing count was included. [3] To validate the methods [1 and 2], Pythagorean equation calculations were used to determine the vertical leg [a] (building height) of a right angle triangle. This research measured the remaining two sides, the hypotenuse [c] and long horizontal leg [b] from a fixed point. A Bosch (PLR 40 C Rangefinder model 0603672300) laser measurement device (with a measurement accuracy of ±2.0 mm) was used to project a laser light onto the base and apex of buildings in the case study laneways to determine the distance from a fixed reference point to the target at which the device was aimed. Thus, the Pythagorean Theorem formula used as it relates to this research to determine [a] was: