Settlement of a Pile under Cyclic Lateral Loads in Dry Sand

It is found through centrifuge model tests that the cyclic lateral load on a pile reduces the shaft friction and induces additional pile settlement. A theoretical model using the load-transfer method was proposed for the settlement prediction of cyclic laterally loaded piles in dry sand. A simple formula was established to quickly predict the pile settlement in practical engineering. The theoretical model provided a reasonable estimate of the pile settlement, while the predictions from the proposed quick prediction formula were relatively conservative. A new concept of “settlement-controlled design” was proposed to advance the methodology for the design of a pile by considering potential settlement after many cycles of lateral loads. According to the design plane derived from this study, the design-state points were suggested to be limited in the convergent zone.

Analysis on the value of stiffness of the dual joint straightness notch joint of beams due to cyclic lateral load

Precast concrete is an answer to the demands of building structures that save time, but cannot be used widely because of the reliability of the connection, especially during an earthquake, the desired earthquake-resistant building structure must have sufficient strength and rigidity. Stiffness is one of the factors that determine the response of a structure to earthquake loads. When connected with earthquake loads, a structure must have sufficient rigidity so that its movement during an earthquake can be limited. This study aims to determine and analyze the stiffness in the double columns straight joint beam notches due to lateral cyclic load. By dividing 3 (three) types of test specimens, namely Monolithic column Beam, Type 1 Column Joint (SBK), and Type 2 Column Beam Joint (SBK). The connection used is a double straight notch and using the grouting method. Testing and analysis using the Displacement Control Method with the European Convention for Constructional Steelwork (ECCS) 1986 standards. The results showed the monolith column Column (BK) specimens have a greater stiffness value compared to SBK 1 specimens and SBK 2 specimens.

Seismic behavior of precast reinforced concrete column-to-foundation grouted duct connections

The paper shows the results of an experimental campaign aimed at investigating the cyclic behavior of a column-to-foundation joint for precast concrete elements. The tested connection is realized adopting corrugated steel ducts embedded into the foundation, in which column protruding rebars are anchored by grouting high performance mortar. The experimental program consists in testing six full-scale reinforced concrete square-section columns subject to quasi-static cyclic lateral load with a constant axial compression. A preliminary series of bond tests was carried out to define some experimental variables, i.e., longitudinal rebar diameter and anchorage length. Results of the precast joints are compared with those of two reference cast-in-place specimens with the same geometric characteristics, showing similar hysteretic behavior, energy dissipation and ductility values. Lastly, the plastic hinge height is computed for all the specimens based on experimental concrete strains, and compared to current codes formulations.

Structural behaviour of insulated foam-timber panels under gravity and lateral loading

A Structural Insulated Panel (SIP) is a structural element of expanded polystyrene insulation (EPS) core sandwiched between two oriented-strand boards (OSB). This research proposes SIPs in low-rise residential construction (i.e. houses and low-residential building), replacing the traditional conventional joist floors and stud walls. This research investigates (i) developing expressions for flexural, compression, monotonic racking and cyclic lateral load capacities of SIPs as compared to the joist/stud wall construction. In this study, the proposed design of SIPs was based on (i) generally established theory for analysis, (ii) assessment of full-scale SIP panels by a loading tester, and (iii) computer modeling using the finite-element modeling. The research program included (i) testing SIP walls in axial compression and bending, (ii) racking and cyclic testing on SIP shear walls, (iii) development of finite-element computer models of the tested SIP panels and verifying those using experimental findings, (iv) correlation between experimental findings and design equations for strength and serviceability available in the literature and wood design Standards. Modification factors of these equations were developed to allow structural engineers to design SIP panels in residential construction more economically reliably. Experimental results showed that SIP panels are being “as good as” the conventional wood-framing of identical sizes, with respect to flexural, compressive, racking and cyclic loading. Also, results showed SIP walls have a greater ability to dissipate energy under racking and cyclic loading that the stud wall system. Therefore, SIP walls can be used so efficient in seismic zones. Based on cyclic lateral load test results, the values of ductility-related force modification factor (Rd) for stud wall, short SIP wall and long SIP wall were calculated as 8%, 22% and 14% lower than the NBCC required value for anchored wall (Rd = 3.0), respectively. In addition cyclic lateral load test results showed that the values of over-strength-related force modification factor (Ro) for stud wall, short SIP wall and long SIP wall were observed to be 17%, 20% and 14% higher than the recommended value of NBCC (Ro = 1.7) for anchored wall, respectively. So, it is concluded that the over-strength factor indicates a confident reserve of resistance in interconnected wall segments.

Structural behaviour of insulated foam-timber panels under gravity and lateral loading

A Structural Insulated Panel (SIP) is a structural element of expanded polystyrene insulation (EPS) core sandwiched between two oriented-strand boards (OSB). This research proposes SIPs in low-rise residential construction (i.e. houses and low-residential building), replacing the traditional conventional joist floors and stud walls. This research investigates (i) developing expressions for flexural, compression, monotonic racking and cyclic lateral load capacities of SIPs as compared to the joist/stud wall construction. In this study, the proposed design of SIPs was based on (i) generally established theory for analysis, (ii) assessment of full-scale SIP panels by a loading tester, and (iii) computer modeling using the finite-element modeling. The research program included (i) testing SIP walls in axial compression and bending, (ii) racking and cyclic testing on SIP shear walls, (iii) development of finite-element computer models of the tested SIP panels and verifying those using experimental findings, (iv) correlation between experimental findings and design equations for strength and serviceability available in the literature and wood design Standards. Modification factors of these equations were developed to allow structural engineers to design SIP panels in residential construction more economically reliably. Experimental results showed that SIP panels are being “as good as” the conventional wood-framing of identical sizes, with respect to flexural, compressive, racking and cyclic loading. Also, results showed SIP walls have a greater ability to dissipate energy under racking and cyclic loading that the stud wall system. Therefore, SIP walls can be used so efficient in seismic zones. Based on cyclic lateral load test results, the values of ductility-related force modification factor (Rd) for stud wall, short SIP wall and long SIP wall were calculated as 8%, 22% and 14% lower than the NBCC required value for anchored wall (Rd = 3.0), respectively. In addition cyclic lateral load test results showed that the values of over-strength-related force modification factor (Ro) for stud wall, short SIP wall and long SIP wall were observed to be 17%, 20% and 14% higher than the recommended value of NBCC (Ro = 1.7) for anchored wall, respectively. So, it is concluded that the over-strength factor indicates a confident reserve of resistance in interconnected wall segments.