Pullout resistance of group suction anchors in parallel array installed in silty sand subjected to horizontal loading – Centrifuge and numerical modeling

• We examine the capacity of group suction anchors in parallel array in silty sand.
• We performed centrifuge model tests and numerical simulations.
• The efficiency of a group anchor was evaluated to quantify the improvement.
• The L/D ratio ranging 1–3 of a unit anchor hardly affects the efficiency.

This study investigates the performance of group suction anchors installed in silty sand and subjected to horizontal pullout loading. The group anchors in this study consist of two or three unit suction anchors rigidly connected to each other in parallel array to improve the pullout resistance. The performance of these group anchors was studied extensively using centrifuge model tests and numerical simulations. The pullout resistances of the group anchors were compared with that of a single anchor. To quantify the improvement, the efficiency of a group anchor was defined as the ratio of the pullout resistance of a group anchor to that of a single anchor multiplied by the number of the unit anchors, and the improvements are discussed. Additional parametric studies were performed using numerical models to study the effect of the physical conditions of the group anchor. The parameters include the L/D ratio of a unit suction anchor, and the spacing between unit suction anchors.