• Title/Summary/Keyword: Load-settlement curve

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Analysis of Load-Settlement Curves in Driven and Embedded Piles (항타 및 매입말뚝의 하중-침하량 곡선의 분석)

  • 천병식;조천환
    • Geotechnical Engineering
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    • v.13 no.6
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    • pp.61-70
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    • 1997
  • Although the load -settlement curve characteristics of embedded piles are different from those of driven piles, for the determination of their allowable loads the same analysis method has been adopted without any considerations. According to the related domestic chi teria, the analysis methods of load-settlement curve have some conflicts among themselves and have several vague points in obtaining the allowable capacity from ultimate or yield capacity. In order to solve those problems, the relevant literatures were reviewed. And also the result of 106 pile load tests was analysed. Analysis result indicates that analysis met hods of the load-settlement curve based on single mathematical curve are not suitable for the general analysis method of load-settlement curves due to their various characteristics. As a result, the appropriate analysis methods and safety factors for the determination of allowable capacity of pile are suggested in this paper.

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Final Settlement Prediction Methods of Embankments on Soft Clay

  • Lee, Dal-Won;Lim, Seong-Hun
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42
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    • pp.68-77
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    • 2000
  • Analyses, in which load was regarded as instant load and gradual step load, respectively, were performed with data measured on a gradually loaded field, and the results were inspected to find the effect of load conditions, and the final settlements which were predicted by Hyperbolic, Tan's, Asaoka's, and Monden's methods were compared with each other. Settlement curves in which load was regarded as instant load and gradual step load being to coincide at twice the time of duration of embankment. On the ground installed vertical drain, from the results of Hyperbolic, Tan's, Asaoka's, Monden's, Curve fitting I, and Curve fitting II (simple, carrillo) methods it was concluded that Asaoka, Curve fitting I, and Curve fitting II methods are reliable for prediction final settlement with back analysis.

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Load-settlement curve combining base and shaft resistance considering curing of cement paste

  • Seo, Mi Jeong;Park, Jong-Bae;Lee, Dongsoo;Lee, Jong-Sub
    • Geomechanics and Engineering
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    • v.29 no.4
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    • pp.407-420
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    • 2022
  • Embedded piles, which are typically used in Korea, are precast piles inserted into prebored ground with cement paste. Dynamic pile tests tend to underestimate the bearing capacity of embedded piles because of the undeveloped shaft resistance prior to the curing of the cement paste and the insufficient energy transferred after the curing. In this study, a resistance combination method using the base resistance before the cement paste is cured and the shaft resistance after the cement paste is cured is proposed to obtain a combined load-settlement curve from dynamic pile tests. Two pairs of embedded piles with diameters of 600 and 500 mm are installed. Each pair comprises one pile for the dynamic pile test and another pile for the static load test. The shape of the load-settlement curve obtained using the proposed method is similar to that obtained from the static load test. Thus, the resistances evaluated using the proposed method at selected settlements are similar to those obtained from the static load test. This study shows that the resistance combination method may be used effectively in dynamic pile tests to accurately evaluate the bearing capacity of embedded piles.

A Study for the Development of Pile Design Method Considering Settlement and Compression (침하량과 압축량을 고려한 말뚝의 설계법 개발을 위한 연구)

  • Lim, Jong-Seok;Ha, Hyuk;Jung, Sang-Kyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1287-1294
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    • 2006
  • A pile is compressed with settlements when loading and bearing capacity is altered along relative displacement of pile/soil on settlement and compression. Settlements of pile displaying limit skin friction is different from displaying tip resistance. Therefore, it is an error in traditional method that bearing capacity of pile is estimated from the sum of limit skin fraction and tip resistance. Accordingly, development of design method considering behavior of load-settlement is needed. In this study, we would like to establish the base for development of design method considering bearing capacity altering along displacement on settlement and compression. For this, we established system and substance of design method. And in order to establish relationship of load-settlement of pile on the type of soil, we analyzed and arranged existing database and pile loading test. On design method, settlement is assumed gradually on each capacity level being assumed gradually. Bearing capacity developing on the pile is obtained on each settlement level. Until the obtained bearing capacity will be equal to assumed capacity, this process is continued with increasing settlement. Load-settlement curve for soil classification is sketched in the process computing settlement on assumed capacity. This design method will be materialized by computation program.

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An Experimental Study on the Relationship between Deformation and Relative Settlement for Weathered-granite (화강풍화토의 변형계수와 상대침하 관계식에 관한 실험적 연구)

  • Park, Yong-Boo
    • Land and Housing Review
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    • v.4 no.1
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    • pp.125-131
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    • 2013
  • To predict the real bearing capacity and settlement of the shallow foundation the plate load test results were used. But there is no field estimation method about igneous weathered soil and rock. Therefore, to predict the settlement equation, the plate load test about igneous weathered soil and rock was done in this study. To analyze the load ~ relative settlement curve by normalization, it did not use normal analysis method, but the load ~ relative settlement (s/B, s : settlement, B : breadth of plate) was used. As a result of normalization by load ~ relative settlement conception, the curve was regular regardless of plate diameter and it was suggested the relationship of in-situ soil condition and results.

The Settlement Characteristics of Large Drilled Shafts Embedded into the Rocks (암반에 근입된 대구경 현장타설말뚝의 침하특성)

  • Hong, Won-Pyo;Yea, Geu-Guwen;Nam, Jung-Man;Lee, Jae-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.9-16
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    • 2005
  • The purpose of this study is to investigate the settlement characteristics of large drilled shafts embedded into bed rocks. To perform this research, 35 pile load test results for the large drilled shafts are used, because these deep foundations generally used as substructure systems for grand bridges. In case of the yield load can not be easily determined by load(P)-settlement(S) curve from the pile load test at the maximum loads, the standard settlements which can determine a yield load is established. The residual settlement equation of pile embedded in gneiss and igneous rocks is presented in this study. Also a equation is proposed to characterize the relationship between loads and elastic settlements in pile load tests on the large drilled shaft embedded into bedrock. Then, large drilled shaft's settlement characteristics are examined on pile length, pile diameter and pile's socked depth into rock at the pile tip.

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Static pile load test and load trasfer measurement for large diameter piles. (대구경 말뚝정재하시험 및 하중전이 측정사례)

  • 최용규
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03a
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    • pp.107-141
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    • 2000
  • Large diameter piles can be defined as piles with diameter of at least 0.76 m (2.5 ft). In bridge foundation, large diameter piles have been used as pier foundations and their use has been increased greatly. In this study, static pile load tests for large diameter piles peformed in Kwangan Grande Bridge construction site were introduced. Also, various sensor installation methods for several types of piles (that is, open-ended steel pipe pile, drilled shafts and socketed pipe piles), pipe axial load measuring method, load transfer analysis method and pile load test results (pile-head load - settlement curve, and pile axial load distribution curve along the pile depth) were introduced.

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A Comparison Study between Top-down Load Test and Bi-directional Load Test Analysis Method in Rock-socketed Small Size Drilled Shaft (암반소켓된 소구경 현장타설말뚝의 정재하시험과 양방향재하시험 분석법 비교연구)

  • Song, Myungjun;Song, Younghun;Jung, Minhyung;Park, Youngho;Park, Jaehyun;Lee, Juhyung;Chung, Moonkyung
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.9
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    • pp.5-12
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    • 2013
  • In this study, each top-down load test and bi-directional load test has been performed on the 480mm diameter of two rock socketed drilled shafts, which are located next to each other, and the results have been compared. The result shows that the settlement from the equivalent load-settlement curve of bi-directional load test is smaller than one from top-down load test, because elastic is not considered in equivalent load-settlement curve of bi-directional load test. Therefore elastic shortening should be considered to obtain appropriate equivalent load-settlement curve. Three existing methods used to obtain equivalent load-settlement curve with consideration of elastic shortening has been compared with the result of top-down load test. The result shows that those existing methods are sufficiently applicable to the design. In addition, result of comparison between top-down load test and bi-directional load test shows that bi-directional load test was found to overestimate bearing capacity because it does not consider pile body failure.