Settlement Characteristics of Split Grouting Pile Composite Foundation in Loess Areas

Abstract

Loess foundations often affect the stability of superstructures due to their insufficient bearing capacities; thus, reinforcement measures are crucial for mitigating the uneven settlement of foundations. This study aims to investigate the settlement characteristics of composite foundations for loess foundations reinforced by splitting grouting piles. First, split grouting tests were carried out on loess foundations. After the test piles reached the design strength, static load tests and geotechnical tests were carried out to obtain the Q-s curves of the test piles. The pile-forming mechanism was analyzed via excavations at an on-site test pile. Furthermore, the traditional settlement calculation method of composite foundations was used to calculate the settlement of split grouting pile composite foundations, and the results were compared with field test results to explore a suitable settlement calculation method of split grouting pile composite foundations. Finally, the numerical model of split grouting pile composite foundations was established according to the pile forming mechanism, and the settlement deformation characteristics of single pile and pile group composite foundations were analyzed. The relative errors of the composite modulus method and the stress correction method for calculating the settlement of the composite foundations were 6.4% and 32.8%, respectively, and the composite modulus method was closer to the test values. The calculated curves of the numerical model were in good agreement with the measured curves and relevant literature research results, demonstrating the rationality of the modeling method; the findings of this study provide theoretical guidance for designing loess foundation splitting grouting reinforcement and for predicting settlement during later construction periods.

Quality evaluation of ground improvement by deep cement mixing piles via ground-penetrating radar

“…At present, DCM piles have been widely used in the treatment of subgrade settlement distress caused by soft loess settlement 24 , 58 – 60 . We have carried out the application and practice of GPR technology in defect detection of DCM piles and quality evaluation of ground improvement based on the construction project of Anlin highway in Gansu Province, China.…”

Assessment of Ultimate Bearing Capacity of Static Loading Pile Based on Cusp Catastrophe Theory

“…Therefore, the mechanical state of a pile can be roughly divided into elastic, elastic-plastic, plastic, and failed state according to the rebound rate of the pile. In some previous studies, the pile state was roughly divided into linear, plastic, and failure stages according to the change trend of the Q-S curves [18]. Here, the Golden Section approach is used to identify the mechanical state of the pile.…”

Research on Static and Dynamic Loading Performance of Geosynthetic Reinforced and Pile-Supported Embankment

“…Wei et al [20] showed that the stress distribution of GPRS embankment is affected by the planar and spatial soil arch effects under dynamic load, and Liang et al [11] found that the existence of geogrids can reduce the influence of dynamic load on the arch effect. To improve the bearing capacity of loess foundations, Zhou et al [21] and Deng et al [22] investigated GRPS embankment for loess foundations reinforced by splitting grouting piles and grouted cement fly ash gravel (CFG) piles. The results show that the structure has good bearing capacity under static load.…”