• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.543-560
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• 2018

With the increased development in downtown underground space facilities that vertically cross under a railway at a shallow depth, the demand for non-open cut method is increasing. However, most construction sites still adopt the pipe roof method, where medium and large diameter steel pipes are pressed in to form a roof, enabling excavation of the inside space. Among the many factors that influence the loosening region and loads that occur while pressing in steel pipes, the size of the pipe has the largest impact, and this factor may correspond to the magnitude of load applied to the underground structure inside the steel pipe roof. The super equilibrium method (SEM) has been developed to minimize ground disturbance and loosening load, and uses small diameter pipes of approximately 114 mm instead of conventional medium and large diameter pipes. This small diameter steel pipe is called an SEM pile. After SEM piles are pressed in and the grouting reinforcement is constructed, a crossing structure is pressed in by using a hydraulic jack without ground subsidence or heaving. The SEM pile, which plays the role of timbering, is a fore-poling pile of approximately 5 m length that prevents ground collapse and supports surface load during excavation of toe part. The loosening region should be adequately calculated to estimate the spacing and construction length of the piles and stiffness of members. In this paper, we conducted a comparative analysis of calculations of loosening load that occurs during the press-in of SEM pile to obtain an optimal design of SEM. We analyzed the influence of factors in main theoretical and empirical formulas applied for calculating loosening regions, and carried out FEM analysis to see an appropriate loosening load to the SEM pile. In order to estimate the soil loosening caused by actual SEM-pile indentation and excavation, a steel pipe indentation reduction model test was conducted. Soil subsidence and soil loosening were investigated quantitatively according to soil/steel pipe (H/D).

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.92-98
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• 2007

Introduction: The treatment of proximal humeral fracture is traditionally determined by Neer's classification system. The severely displaced three-part or four-part fracture is an indication for primary hemiarthroplasty. The current authors report the clinical results of 10 patients who received hemiarthroplasty for proximal comminuted fractures. The minimum follow-up period was 12 months. Materials and Methods: The current authors studied 10 patients who, between July 1999 and March 2005, each received hemiarthroplasty for a proximal humeral fracture of one shoulder. According to Neer's classification system, 5 of the patients had three-part fractures, and 5 of the patients had 4-part fractures. The mean interval between trauma and hemiarthroplasty was 6.1 days. The mean age of the 6 female and 4 male patients was 67.4 years(range: 56 to 76). Shoulder function was evaluated using the Constant score, the Simple Shoulder Test, and the modified UCLA score. Results: The mean Constant score was 51.4(range: 34 to 60). The mean modified SST score was 7.8 out of 12 tasks. Excluding the one patient who had also sustained an axillary artery rupture and a brachial plexus injury after the initial trauma, the mean Constant score for the remaining 9 patients was 53.5(range: 44 to 60), and the mean SST score was 7.2 tasks. The modified UCLA score averages for pain, function, and active forward flexion and strength were, respectively, 8.2($6{\sim}10$), 6.6($2{\sim}8$), and 6.9($4{\sim}8$). The total UCLA score was an average of 21.7($12{\sim}26$). Patients' the modified UCLA ratings were as follows: Excellent: 3, Good: 6, and Poor: 1. The patient with the poor outcome was the one who had also sustained the neurovascular injury. Patient's subjective satisfaction rating were as follows: Excellent: 2, Good: 7, and Poor: 1. Conclusion: Based on short term follow-up results, this study indicates that hemiarthroplasty is the treatment of choice for proximal humeral fractures on which it would be difficult to perform open reduction and internal fixation. Hemiarthroplasty is a useful treatment modality to prevent shoulder stiffness and to allow daily living tasks in elderly patients. However, restoration of muscle power and range of joint motion were not recovered satisfactorily.