A numerical study into the evolution of loads on shores and slabs during construction of multistorey buildings. Comparison of partial striking with other techniques

Abstract

_____________________________________________________________________________________ AbstractThis paper contains a summary and evaluation of an experimental research project carried out at the ICITECH laboratories, Valencia, Spain. The project consisted of the construction of a full-scale building that included a process of shoring, clearing and striking (SCS). The experimental model was used as the basis for the development of a FE model, including an evolving calculation, with the objective of simulating the construction process used, as well as studying the evolution of concrete properties during the test. The FE model was verified with the results obtained from the experimental model. Two further FE models were then developed from the original model and were used to simulate the construction of the same building using two different construction processes: one involving shoring and striking (SS) and the other shoring, re-shoring and striking (SRS). Finally, the SCS was compared to the SS and SRS processes, respectively, and an analysis was made of the advantages and disadvantages of each one. The paper breaks new ground in that for the first time ever a comparative study is made of the three most frequently used shoring techniques.

Temperature effects on load transmission between slabs and shores

“…However, later studies by other authors such as Liu et al [8], Stivaros & Halvorsen [9], Chen Mosallam [10], Duan & Chen [11], Moragues et al [4], Fang et al [12], Beeby [13] and Alvarado et al [5] agree that Grundy & Kabaila's simplified method [7] overestimates the loads on shoring, mainly due to the fact that the latter authors consider shores to be infinitely stiff. This factor is crucial in considering the effects of clearing, as pointed out by Alvarado et al [6] , Alvarado [14] and Calderón et al [15].…”

“…To simulate the experimental building described in Section 2.1, a model based on Alvarado's FEM [6] was developed, using commercial ANSYS 11.0 software [19]. The model considered changes in ambient temperature as well as in temperatures of slabs, shores and columns.…”

“…It consists of reducing the number of support components by removing, some days after pouring, the formwork and over 50% of the shores that support the floor slabs, while ensuring that the remaining shores stay in contact with the structure. To date, few authors have studied the clearing technique, and only Moragues et al [4] and Alvarado et al [5,6] have carried out experimental and theoretical studies on its application. Other theoretical and experimental studies on load transmission between shores and slabs have not taken the clearing technique into consideration.…”

“…The results have been used to determine the influence of temperature changes on load variations on shores by developing a theoretical finite element model. The FE model developed by Alvarado et al [6] was used to simulate the building while introducing the temperature changes that occurred in the different structural elements during the construction process. The results from the model were compared with the load measurements obtained from the shores in the experimental building to verify that this building correctly reproduced the appropriate behaviour patterns.…”

Improving construction processes of concrete building structures using load limiters on shores

“…Numerous authors have proposed a multitude of theoretical models to estimate shore/slab load transmission, including complex models such as those based on the finite element method [4][5][6][7][8][9][10] and simple calculation methods. Among others, Grundy and Kabaila [11], Duan and Chen [12], Fang et al [13] and Calderón et al [14] developed simplified methods to estimate load transmission between slabs and shores in multistorey buildings.…”