Performance evaluation of post-grouting for bored piles installed in inhomogeneous gravel pebble stratum overlaid by deep and soft soil layers

ABSTRACT

To study the behaviours of post-grouted piles installed in an uneven pebble bearing layer overlaid deep and soft soil layer in Wenzhou, China, static loading field tests of three bored post-grouted piles were conducted, considering the key design parameters of post-grouting including the grout volume, grout pressure, and bearing capacity. According to the on-site geological conditions in the region, the theoretical values were calculated through applying different calculation equations for these three parameters, and the actual values obtained from the field tests were investigated to assess the improvement effect of load-bearing performance of grouted piles installed in these geological conditions as an extremely uneven pebble-bearing layer overlaid by the deep and soft soil layer. The calculation equations of key design parameters of post-grouting in this type of soil layers were then proposed. This study could provide a reference to evaluate the performance of post-grouted piles under various grouting parameters in analogical soil layers.

KEYWORDS:

• Deep-silt layer
• Pebble-bearing layer
• Cast-in Bored pile
• Post grouting
• Static loading test
• Axial bearing capacity

Acknowledgments

This research was supported by the National Science Foundation for Young Scientists of China (52008318), Wenzhou association for science and technology (KJFW41), Education Department of Zhejiang Province (Y202146717 and Y202248839), the Master’s Innovation Foundation of Wenzhou University (316202101061), the College Students’ innovation and entrepreneurship training program of Wenzhou University (JWXC2021194 and JWXC2022200) and Wenzhou Univeristy (2023kxfz098). The financial support is gratefully acknowledged. Thanks are also extended to Zhejiang XiaTai Foundation Engineering Co., Ltd. for the support in the filed tests.

Disclosure statement

No potential conflict of interest was reported by the authors.

Statements and Declarations

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

The work was supported by the NSF [52008318], Wenzhou Univeristy [2023kxfz098], Education Department of Zhejiang Province [Y202146717,Y202248839], Wenzhou association for science and technology [KJFW41], the College Students’ innovation and entrepreneurship training program of Wenzhou University [JWXC2021194,JWXC2022200] and the Master’s Innovation Foundation of Wenzhou University [316202101061].