# Experimental Evaluation of Load Distribution between Piles in Case of Block Failure
## 3 Results Obtained from Experiments  
When the data obtained as a result of the experiments were examined, the load distribution between piles in small settlement, similar to the results of the studies in the literature, as seen in Figure 8a, showed that corner piles carried more load compared to the center piles. In the case of excessive settlement conditions, the corner piles carried less load than the center piles, as in Figure 8b. The load settlement graph obtained as a result of loading the piled raft foundation is as in Figure 9. In this figure, as a result of loading, the bearing capacity of the piled raft foundation and the failure point is clearly seen. The variation of the \(\text{q}_{\text{cor}}/\text{q}_{\text{Gen}}\) ratio with the settlement amount is as shown in Figure 10. As seen in the figure, corner piles carried a higher load than the center pile at small settlement values. However, as the settlement value increases, this situation was reversed. The graph in Figure 10 was obtained by taking the average of the \(\text{q}_{\text{cor}}/\text{q}_{\text{Gen}}\) ratio obtained as a result of the experiments performed on all foundation types and soils used in the study. Figure 7: Fixing and calibration of strain gauges on piles (**a**); placement of strain gauges on pile raft foundations used in experiments (**b**). The qcor/qgen ratio obtained from other studies in the literature and the qcor/qgen ratio obtained as a result of this study are given in Table 4 at small settlement values. Figure 8: Variation of load distribution between piles: small settlement conditions (**a**), excessive settlement conditions (**b**). Figure 10: qcor/qgen ratio vs. settlement in average results from all experiments. Figure 9: Load vs. settlement for 4D pile spacing with 9 piles and consolidation pressure of 100 kPa. Corner and center pile load-bearing ratios (\(\mathrm{q_{cor}}/\mathrm{q_{gen}}\)) are shown in detail in Figures 7b and 11 in cases where the settlement amount increases. In Figure 11, the corner pile (S1) started to carry a higher load than the center pile (S6) in the initial state where the settlement values were small. However, as the amount of settlement with the load increased, the foundation failure and the center pile (S6) started to carry more load compared to the corner pile (S1). As can be seen from the test results, as the soil consolidation pressure increased, the corner piles started to carry more load than the center piles at small settlement amounts. However, when the settlements after failure were examined, it was observed that the corner piles started to carry less load than the center piles. In the experiments, it has been observed that the soil between the piles behaves like a block and moves as if it is a single piece in the soil. As seen in Figure 12, there are studies in the literature in which the block effect was detected ([PERSON] et al., 2013). After loading, a fracture surface forms around the block, and this causes the soil between the piles to behave like a block. This fracture surface become evident when the piled foundation begins to experience excessive settlement. Therefore, no fracture surface is formed around the block before the failure and the corner piles carry a higher load than the center ones. As seen in Figure 13a, it has been observed that no blocks are formed in the pile foundations that settle within the allowable limits and the piles can be withdrawn without breaking the soil. However, in the case of excessive settlement, it was determined that the block was formed, and a fracture surface was formed around the pile as seen in Figure 13b. While the piles were being pulled out of the soil, the block fracture surface formed around the piles was checked and this situation was clearly observed (Figure 13c).