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The demand for a load distributive compression anchor (LDCA) in construction sites has been increasing, owing to its high bearing capacity and removable steel strands. As an LDCA comprises multiple anchor bodies and unbonded steel strands, the load applied to the strands generates a distributive compressive stress in the grout, preventing high concentration of grout–ground shear stress. Unlike in the conventional anchors, in an LDCA, independent load transfer of each anchor body induces interference effect between adjacent anchor bodies. Therefore, for an efficient design of an LDCA, it is necessary to investigate the load transfer mechanism considering the effect of multiple anchor bodies. In this study, a series of anchor pull-out field tests was conducted for LDCAs consisting of a single anchor body, and double and triple anchor bodies spaced by 1, 2, and 3 m. According to the test results, the LDCA showed a stiffer load–displacement behavior with an increase in the number and spacing of the anchor bodies. The multiple anchor bodies of the LDCA generated an overlapping of the grout axial load and induced its rapid dissipation, increasing the grout–ground shear stress. This interference effect was more clearly observed with a decrease in the anchor body spacing.

As an LDCA consists of multiple anchor bodies and unbonded tendons, the load applied to the tendon is transmitted to grout and ground by the movement of each anchor body installed along the anchor length. Therefore, the load transfer behavior of LDCA is affected by the interference between adjacent anchor body, and the effect of multiple anchor bodies should be considered in the LDCA design. This study performed a series of pull-out field tests on LDCAs installed in soft rock. LDCAs were designed to have various number and spacing of anchor bodies to investigate the effect of multiple anchor bodies. Furthermore, the test results were compared with the results of pull-out field tests conducted on weathered rock to examine the effect of ground conditions. The load-displacement relationship showed that the grout failure occurred in the LDCA installed in soft rock, and thus the ultimate bearing capacity was smaller than that of the LDCA installed in weathered rock. Additionally, the grout axial load distribution indicated that the LDCA installed in soft rock expressed tensile stress in the grout due to the effect of multiple anchor bodies leading to the tensile failure on the grout.

Soluble boron-free reactors inherently have larger reactivity feedback than conventional pressurized water reactors during power transients. The purpose of this study is to verify the capability of the long-term load follow operation with only control rods for the soluble boron-free small modular reactors. The effects of the long-term load follow operation on burnup distribution, power distribution, reactivity balance and spatial xenon stability are investigated throughout the whole cycle. The reactivity balance results show that the control rod design of the soluble boron-free SMR successfully manages the reactivity changes introduced by power and xenon changes during the daily load follow operation. The spatial xenon stability analysis demonstrates that the SMR model has enough capability to suppress the axial and quadrant xenon oscillation without a second peak during the load follow operation. The load follow simulation results showed that safety parameters including peaking factor, axial offset and shutdown margin satisfy design limits.