scholarly journals The Analytical Solution of the Grouting Migration Height for the Post-Grouted Drilled Shaft Based on the Herschel-Bulkley Model

2021 ◽  
Author(s):  
Gan Nan ◽  
Haiming Liu ◽  
Yanjie Zhang ◽  
Wenyun Ding ◽  
Jing Cao ◽  
...  
Keyword(s):  
Pile Foundation ◽  
Engineering Practice ◽  
Drilled Shaft ◽  
Layered Soils ◽  
Stress Release ◽  
Pile Shaft ◽  
Bored Pile ◽  
Pile Diameter ◽  
Grouting Pressure ◽  
Iterative Calculation

The traditional bored pile technology has some arduous problems, such as the sediment at the pile tip, the mud skin along the pile shaft, and the stress release due to borehole construction. The post-grouted technology at the pile tip of bored pile has emerged because of demand. The grouting migration height (GMH) is of great significance to the strengthen and reinforcement of the pile foundation. This paper derives the calculation formula of the GMH based on the theory of the column hole expansion and Herschel-Bulkley model. The influence of relevant parameters on the GMH is discussed. Aiming at the problem of the grouting migration along the pile shaft in layered soils, the iterative calculation method of the GMH is proposed. The correctness of the GMH is verified by an engineering case, which can guide the engineering practice. The result shows that the GMH increases with the increase of the grouting pressure, the pile diameter and the thickness of the mud skin, and the grouting pressure is positively correlated with the GMH. The GMH decreases with the increase of the buried depth, the consistency coefficient and the rheological index. On this basis, the correctness of the GMH is verified by an engineering case.

Expansive concrete drilled shafts

1985 ◽  
Vol 12 (2) ◽  
pp. 382-395 ◽  
Author(s):  
Shamim A. Sheikh ◽  
Michael W. O'Neill ◽  
M. A. Mehrazarin
Keyword(s):  
Load Transfer ◽  
Stress Path ◽  
Drilled Shafts ◽  
Drilled Shaft ◽  
Cement Concrete ◽  
Bored Pile ◽  
Expansive Concrete ◽  
Stiff Clay ◽  
Expansive Cement

A hypothesis is presented in this paper that states that expansive cement concrete produces a stronger bond between the concrete in a drilled shaft (bored pile) and the surrounding soil than does normal cement; this results in an increase in the frictional component of capacity and a reduction in the settlement of the shaft at working load levels.Four types of expansive cement, type "K" cement (the expansive cement available commercially) and three made from commercially available materials, were tested for their expansion characteristics; two of them were selected to be used in two instrumented drilled shafts in stiff clay. Normal (type 1) cement was used in a third shaft to serve as a reference. The three shafts were tested to failure after essentially all the expansion was deemed to have taken place in the two expansive concrete shafts. Lateral and longitudinal expansion of the shafts were monitored during the curing period. Load–settlement behaviour and load transfer between shafts and soil during the tests were studied.The test results permitted the preliminary conclusion that expansive cement concrete can increase the frictional capacity of drilled shafts in stiff clay by as much as 50% and reduce the settlement by about 50%. The results are valid for short-term behaviour of drilled shafts made of expansive cement. The long-term behaviour of such shafts remains to be studied. Key words: base bearing capacity, bored pile, cement (expansive), concrete (structural), drilled shaft, ettringite, expansion, frictional capacity, settlement, stress path.

Analysis for Dynamic Response of Buried Steel Pipeline in Cross-Anisotropic Layered Soils

2020 ◽  
Vol 20 (07) ◽  
pp. 2071006
Author(s):  
Jin Zhang ◽  
Zejun Han ◽  
Hongyuan Fang ◽  
Linqing Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Dynamic Stiffness ◽  
Engineering Practice ◽  
Layered Soils ◽  
Buried Pipeline ◽  
Network Systems ◽  
The Time Domain ◽  
Element Method

The interaction between underground pipelines and soils is crucial to the design and maintenance of underground pipeline network systems. In this paper, the dynamic stiffness matrix in the frequency-domain of the buried pipeline is obtained by the improved scaled boundary finite element method (SBFEM) coupled with the finite element method (FEM) at the interface between the far and near fields. A new coordinate transformation together with a scaled line is introduced in the improved SBFEM. Combined with the mixed variable algorithm, the time-domain solution of the buried pipeline under dynamic loads is then obtained. The accuracy of the proposed algorithm was verified by numerical examples. A parametric study is performed to assess the influence of the anisotropic characteristics of the layered soils on the dynamic response of the pipeline, the result of which provides a reliable basis for engineering practice. The results show that these parameters have a significant impact on the pipeline. The understanding of this impact can contribute to the design, construction, and maintenance of the corresponding engineering projects.

The Application Research and Discussion on a Viaduct Artificial Excavated Pile Technology

2012 ◽  
Vol 446-449 ◽  
pp. 2449-2452
Author(s):  
Dong Guo Li ◽  
Gui Mei Shi
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Retaining Wall ◽  
Wall Effect ◽  
Construction Technology ◽  
Application Research ◽  
Technical Work ◽  
Bored Pile

A viaduct of the Qinglai expressway fourth contract was artificial excavated piles. The construction technical work was regarded as an example. The technical comparison were done between the artificial excavated pile and the bored pile on the pile foundation bearing capacity and the retaining wall effect . The artificial excavated pile replacing the bored pile was feasible, and the construction technology and the key problems of the artificial excavated piles were confirmed. The references were provided to the similar projects.

Experimental Program of Indoor Model Research about Single Pile Negative Friction

2014 ◽  
Vol 501-504 ◽  
pp. 160-165
Author(s):  
Chang Liu Chen ◽  
Song Qi Wei ◽  
Shuai Hua Ye ◽  
Yan Liu
Keyword(s):  
Skin Friction ◽  
Pile Foundation ◽  
Scale Model ◽  
Experimental Program ◽  
Engineering Practice ◽  
Negative Skin Friction ◽  
Friction Resistance ◽  
Model Research ◽  
Reduced Scale ◽  
Selection Of

This article aims to study the influence of negative skin friction resistance of waterishlogged pile foundation, through indoor scale model test of pile foundation in the loess areas. The program involved in the model similar than design, the model groove design, the selection of test materials, the design of the ground soil, the layout of measuring points and the research of load method in the test. Through the experimental study on the reduced scale model, we can deepen the understanding of the action mechanism of negative skin friction resistance of the pile, which could guide the engineering practice and design.

scholarly journals Transient unsaturated shaft resistance of a single pile during water flow

2021 ◽  
Vol 337 ◽  
pp. 03007
Author(s):  
Daniel Batista Santos ◽  
Moisés Antônio da Costa Lemos ◽  
André Luís Brasil Cavalcante
Keyword(s):  
Unsaturated Soil ◽  
Soil Mechanics ◽  
Engineering Practice ◽  
Moisture Condition ◽  
Shaft Resistance ◽  
Pile Shaft ◽  
Resistance Variation ◽  
Unsaturated Soil Mechanics ◽  
Tropical Weather ◽  
Unsaturated Condition

The pile foundations’ design is commonly based on the soil’s initial in situ condition during field investigations or the assumption of its saturated condition. However, for some regions in tropical weather, a significant part of the pile shaft remains above the groundwater table (i.e., unsaturated condition) during the structure’s lifespan. Only considering a constant moisture condition in the soil (unsaturated or saturated) can overestimate or underestimate the pile design. The soil shear strength governs the shaft resistance of a pile and depends on the soil matric suction, which is significant in the unsaturated zone. In this study, an analytical model is proposed to estimate piles’ unsaturated shaft resistance and encourage the use of unsaturated soil mechanics in engineering practice. The mathematical equation involves well-known parameters from unsaturated soil mechanics theory and simulates the pile shaft resistance variation with its length and time, considering a unidimensional infiltration downwards (e.g., during a rainfall event).

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