• Title, Summary, Keyword: SPT

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Prediction of End Bearing Capacity for Pre-Bored Steel Pipe Piles Using Instrumented Spt Rods (SPT 에너지효율 측정 롯드를 이용한 매입말뚝의 선단지지력 예측)

  • Nam, Moon S.;Park, Young-Ho;Park, Yong-Seok
    • Journal of the Korean Geotechnical Society
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    • v.29 no.12
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    • pp.105-111
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    • 2013
  • The standard penetration test (SPT) has been widely used because of its usability, economy, and many correlations with soil properties among other factors. In SPT, hammer energy is an important factor to evaluate and calibrate N values. To measure hammer energy, an instrumented SPT rod was developed considering that stress waves transferring on rods during SPT driving are the same as stress waves transferring on piles due to pile driving. Using this idea, an instrumented SPT rod with a pile driving analyzer was applied as a pile capacity prediction tool in this study. In order to evaluate this method, SPT and dynamic cone tests with the instrumented SPT rod were conducted and also 2 pile load tests were performed on pre-bored steel pipe piles at the same test site. End bearings were predicted by CAPWAP analysis on force and velocity waves from dynamic cone penetration tests and SPT. Comparing these predicted end bearings with static pile load tests, a new prediction method of the end bearing capacity using the instrumented SPT rod was proposed.

Correlations between the CPT and the SPT for the Residual Soil in Korea (국내 잔류토층에서 CPT와 SPT와의 상관관계에 대한 연구)

  • Koo, Ja-Kap;Yi, Chang-Tok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.3
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    • pp.231-239
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    • 2003
  • Many foundation jobs have been designed and constructed in Korea with the sole information obtained from the SPT. The use of the CPT to estimate equivalent SPT values is becoming a common application for foundation design. The relationship between the CPT and the SPT has been determined in a number of studies over the past three decades. However a few papers have been published on the relationship between the CPT and the SPT in residual soil. Due to the large variation in published correlations between qt and N in residual soil, local correlations should be developed wherever possible. CPT tests have been carried out in the residual soil classified by SM in accordance with USCM and compared with SPT. Value of qt/N = 0.3 have been suggested for residual soil in Korea.

Evaluation of near surface Vs distribution by using SPT uphole method (SPT 업홀기법을 이용한 지반의 2차원 전단파 속도 분포 도출)

  • Kim, Dong-Soo;Bang, Eun-Seo;Kim, Jong-Tae
    • 한국지구물리탐사학회:학술대회논문집
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    • pp.93-116
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    • 2005
  • SPT-Uphole tomography method was introducedand verified in this paper. In SPT-Uphole method, SPT (Standard Penetration Test) which is common in site investigation, was used as a source and several surface geophones in line were used as receivers. Shear wave velocity (Vs) distribution map which has triangular shape around the boring point can be obtained by tomography inversion. The factors for obtaining reliable result of SPT-Uphole tomography are exact travel time information and accurate inversion method. To establish of the SPT-Uphole tomography procedure, the most reliable method for obtaining exact travel time information and verification of tomography inversion method were studied by using theoretical travel time information and finite element method (FEM) analysis. finally, SPT-Uphole tomography method was performed at the weathered soil site in Kimje. By comparing with several boring data including SPT-N value, feasibility of this method was verified in the field.

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A Study on the Target Position Estimation Algorithm to Radar System (레이더 시스템에서 목표물 위치추정 알고리즘에 대한 연구)

  • Lee, Kwan-Houng;Song, Woo-Young
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.5
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    • pp.111-116
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    • 2008
  • Radar system must estimate exactly quickness and target in interference channel. Because interference of radio channel is multipath channel by artificial structure and nature structure. signal estimation is difficult. As long as, get rid of interference signal have been study digital beamforming, adaptive array antenna and so on. In this paper, proposed SPT-SALCMV beamforming algorithm get rid of coherent interference algorithm and adaptive array antenna. Adaptive array forms null pattern and reduces gains for direction of interference signal. And estimate signal that want by keeping gains of beam pattern changelessly to target signal direction. In this paper, proposed SPT-SALCMV algorithm was exactly received position of target. But general SPT-LCMV algorithm resulted beam error about 30degrees. Therefore, proved that SPT-SALCMV algerian that propose in this paper is more excellent than genaral SPT-LCMV algorithm.

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Will Prone Trunk Extension Affect Scapular and Thoracic Kinematics and Muscle Activities During Scapular Posterior Tilting Exercise in Subjects With Round Shoulder and Flexed Posture?

  • Shin, A-reum;Lee, Ji-hyun;Kim, Da-eun;Cynn, Heon-seock
    • Physical Therapy Korea
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    • v.25 no.4
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    • pp.1-8
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    • 2018
  • Background: Round shoulder posture, results from excessive flexed posture of the thorax, is defined as a position of scapular protraction, anterior tipping, and downward rotation. However, previous studies have focused on only passive position of the thorax during scapular posterior tilting (SPT) and have not reported on SPT combined with correction of flexed posture. Objects: The aim of this study was to compare effects of SPT and SPT with prone trunk extension (SPT + PTE) on activities of the lower trapezius, serratus anterior, and thoracic erector spinae and degree of posture in subjects with round shoulder and flexed posture. Methods: Fifteen subjects with round shoulder and flexed posture were recruited. The caliper was used to measure the degree of round shoulder and flexed posture. Electromyography was performed to collect data of muscle activities. Paired t-test was used to compare two exercise (${\alpha}=.05$). Results: When SPT + PTE was applied, the degree of round shoulder posture (p=.001) and flexed posture (p=.039) significantly decreased compared with that when SPT was applied. The lower trapezius activity significantly increased in the SPT + PTE condition compared with that in the SPT condition (p=.026). There were no significant differences in serratus anterior activity between SPT + PTE and SPT. The thoracic erector spinae activity significantly increased in the SPT + PTE condition compared with that in the SPT condition (p=.014). Conclusion: SPT + PTE might be one of the effective methods to enhance activities of lower trapezius and thoracic erector spinae, and to reduce round shoulder posture and flexed posture in subjects with round shoulder and flexed posture.

Evaluation of Near Subsurface 2D Vs Distribution Map using SPT-Uphole Tomography Method (SPT-업홀 토모그래피 기법을 이용한 지반의 2차원 전단파 속도 분포의 도출)

  • Bang, Eun-Seok;Kim, Jong-Tae;Kim, Dong-Soo
    • Journal of The Korean Society of Civil Engineers
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    • v.26 no.3C
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    • pp.143-155
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    • 2006
  • SPT-Uphole tomography method was introduced for the evaluation of near subsurface shear wave velocity (Vs) distribution map. In SPT-Uphole method, SPT (Standard Penetration Test) which is common in geotechnical site investigation was used as a source and several surface geophones in line were used as receivers. Vs distribution map which is the triangular shape around the boring point can be developed by tomography inversion. To obtain the exact travel time information of shear wave component, a procedure using the magnitude summation of vertical and horizontal components was used based on the evaluation of particle motion at the surface. It was verified that proposed method could give reliable Vs distribution map through the numerical study using the FEM (Finite Element Method) model. Finally, SPT-Uphole tomography method was performed at the weathered soil site where several boring data with SPT-N values are available, and the feasibility of proposed method was verified in the field.

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Effects of Verbal Cue for Scapular Depression During Scapular Posterior Tilt Exercise on Scapular Muscle Activities and Clavicular Tilt Angle in Subjects With Rounded Shoulder Posture and Upper Trapezius Myofascial Pain

  • Choi, Sil-ah;Cynn, Heon-seock;Shin, A-reum;Kim, Da-eun
    • Physical Therapy Korea
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    • v.24 no.3
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    • pp.30-39
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    • 2017
  • Background: Scapular posterior tilt (SPT) is important in the prevention of abnormal scapular movement and pain during elevation of the arm. However, previous studies have overlooked increased upper trapezius (UT) muscle activity interrupting the normal force couple of scapular motion and compensation of levator scapulae (LS) muscle activated simultaneously with UT during SPT exercise. Objects: The purpose of this study was to compare the effects of modified SPT with depression exercise versus SPT exercise on serratus anterior (SA), lower trapezius (LT), UT, and LS muscle activities and the clavicular tilt angle, in subjects with rounded shoulder posture (RSP) and myofascial pain in the UT muscle region. Methods: Eighteen subjects with RSP were recruited and randomly allocated to 2 groups; 9 in the SPT group and 9 in the SPT with depression group. All subjects met the specific RSP criteria and had myofascial pain of UT region. Depending on the allocated group, subjects performed the assigned SPT exercise and EMG data were recorded during the each exercise. Clavicular tilt angle was defined as the angle between the line joining the medial and lateral end of the clavicle and a horizontal line. Results: The SA muscle activity was significantly greater in SPT with depression than with SPT exercise (p<.05). The UT, LS muscle activity and the clavicular tilt angle was significantly lower in SPT with depression than with SPT exercise (p<.05). Conclusion: These findings were insightful because the potential risk of pain from overactivation of the UT and LS was considered, in contrast with SPT exercise. SPT with depression exercise can be implemented as an effective method to facilitate scapular muscle activity for stability and to prevent myofascial pain in the neck and shoulder.

Evaluation of prognosis related to compliance with supportive periodontal treatment in patients with chronic periodontitis: a clinical retrospective study

  • Lee, Jong-Bin;Shin, Hye-Jung;Kim, Dae-Yeob;Pang, Eun-Kyoung
    • Journal of Periodontal and Implant Science
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    • v.49 no.2
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    • pp.76-89
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    • 2019
  • Purpose: The purpose of this study was to evaluate the prognostic effect of patient compliance with supportive periodontal treatment (PC-SPT). Chronic periodontitis patients were classified based on their compliance level, and factors affecting PC-SPT and the prognosis of PC-SPT were investigated. Methods: This study selected 206 patients who started SPT after receiving periodontal treatment between 2010 and 2012. Patients who continued SPT through February 2016 were included. The patients were classified according to whether they exhibited complete compliance (100% of visits), excellent compliance (${\geq}70%$ of visits), incomplete compliance (<70% of visits), or non-compliance (only 2 visits). Patient characteristics that could affect PC-SPT, such as age, sex, distance of the clinic from their residence, implantation, and periodontal treatment, were investigated. The number of newly decayed and extracted teeth, alveolar bone level changes around the teeth and implants, and implant removal were examined to evaluate the prognosis of PC-SPT. Results: Sex and the presence of an implant significantly affected PC-SPT. Additionally, the number of newly decayed and extracted teeth and changes in alveolar bone levels around the teeth and implants were significant prognostic factors related to PC-SPT. Conclusions: PC-SPT in chronic periodontitis patients will help maintain periodontal health and prevent further periodontal disease.

Modification of SPT-Uphole Method using Two Component Surface Geophones (2방향 지표면 속도계를 활용한 SPT-업홀 기법 개선 연구)

  • Bang, Eun-Seok;Kim, Jong-Tae;Kim, Dong-Soo
    • Journal of The Korean Society of Civil Engineers
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    • v.26 no.2C
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    • pp.109-120
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    • 2006
  • SPT-Uphole test is a seismic field test using receivers on ground surface and a SPT (Standard penetration test) source in depth. Even though this method is simple and economic, it makes hesitate to apply in real field that it is difficult to obtain reliable travel time information of shear wave because of the characteristics of SPT impact source. To overcome this shortcoming, in this paper, modified SPT-Uphole method using two component surface geophones was suggested. Numerical analysis was performed using finite element method for understanding the characteristics of surface motion induced by in-depth vertical source, and comparison study of the various methods which determine the travel time information in SPT-Uphole method was performed. In result, it is thought that the most reasonable method is using the first local maximum point of the root mean square value signals of vertical and horizontal component in time domain. Finally, modified SPT-Uphole method using two component surface geophones was performed at the site, and the applicability in field was verified by comparing wave velocity profiles determined by the SPT-Uphole method with the profiles determined by SASW method and SPT-N values.

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Effect of supportive periodontal therapy on long-term implant survival rate

  • Choi, So-Jeong;Kim, Ok-Su
    • Oral Biology Research
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    • v.42 no.4
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    • pp.228-234
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    • 2018
  • The aim of this study was to determine the condition of supportive periodontal therapy (SPT) in implant patients and the effect of SPT on implant long-term survival. Implants placed at the Dept. of Periodontology, Chonnam National University Dental Hospital over a 5-year period, were traced for up to 8 years. Patients who had visited the hospital at least once a year were defined as regular SPT, and patients who were treated by active periodontal therapy were defined as patients with periodontitis. Kaplan-Meier survival analysis was performed based on the observation periods, and the effect of SPT and history of periodontitis on implant survival assessed by chisquare test. A total of 183 patients (age: 21-91, 98 males and 85 females), and 508 implants were used for this study. Three hundred eight implants were under SPT and 87 implants was under regular SPT. For the patients with periodontitis 136 implants were placed. The 5-year survival rate was 94.8%. The overall survival rate in patients who received SPT was 97.1% and 91.0% for those who did not (p=0.004). The survival rate in patients who received regular SPT was 97.7%, and 96.8% for patients received irregular SPT. The survival rate was 93.4% in patients with periodontitis and 95.2% in patients without periodontitis. Among patients with periodontitis, the survival rate was 100.0% in patients who received regular SPT and 89.2% for irregular SPT (p=0.012). These results suggest that regular SPT improves implant survival rate and is more effective in patients with periodontitis.