Model test of lateral and end combined grouting of bridgecastinplace pile foundation in Loess Area(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2021年6期
- Page:
- 19-28
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Model test of lateral and end combined grouting of bridgecastinplace pile foundation in Loess Area
- Author(s):
- XUE Zhennian1; FENG Hongming2; REN Chenning3; ZHOU Zhijun2
- (1. Shaanxi Communications Holding Group Co., Ltd., Xian 710075, Shaanxi, China; 2. School ofHighway, Changan University, Xian 710064, Shaanxi, China; 3. China Railway FirstSurvey and Design Institute Group Co.[KG-*4], Ltd.[KG-*4], Xian 710043, Shaanxi, China)
- Keywords:
- road engineering; lateral and end combined grouting; model test; bridge castinplace pile; pile side resistance
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to study the influence of lateral and end combined grouting technology on the bearing characteristics of bridge castinplace piles foundation in Loess Area. A new type of lateral and end combined grouting device was developed based on the traditional grouting device. Indoor model tests were carried out on model piles with different grouting methods, the bearing capacity, axial force and side friction curves of each model pile were analyzed to evaluate the grouting effect of the new combined grouting device. After the static load test, the model box was excavated to obtain the distribution of grout veins, analyze the law of grout diffusion in the loess, and explore the mechanism of improving bearing characteristics of pile foundation in Loess Area. The results show that the lateral and end combined grouting technology is better than the pile end grouting technology, in improving the bearing capacity of the pile foundation in the Loess Area. Compared with the conventional model pile S1, the ultimate bearing capacity of pile end grouting pile S2 is increased by 29%, and the ultimate bearing capacity of lateral and end combined grouting pile S3 is increased by 71%, which has the same grouting quantity whit S2. Under the action of ultimate load, the end resistance ratios of S1, S2 and S3 pile are 19.2%, 43.33% and 34.9%, and the side resistance ratios are 80.80%, 56.67% and 65.1% respectively. The lateral and end combined grouting technology has changed the characteristics of small at both ends and large in the middle of the side friction curve of pile foundation in Loess Area, showing an Rshape with large at both ends and small in the middle. The overall value has been improved, and the characteristics of asynchronous play have been improved to some extent. No matter what kind of grouting method, the main diffusion methods of slurry in loess are compaction grouting and splitting grouting. The bottoms of pileend grouting pile and combined grouting pile have formed cylindrical mortar solidified material and 3 obvious slurry veins. At the same time, the slurry returnheight of combined grouting pile reaches 60 cm, which makes the average diameter of the lower pile body increase by 1 to 1.5 cm. The grouting effect of combined grouting nozzle is remarkable, which can provide reference for the design and construction of combined grouting of pile foundation in Loess Area. 3 tabs, 13 figs, 28 refs.
Last Update: 2021-12-14