Sand Drain과 Sand Compaction Pile로 보강된 연약지반의 안정성 검토

안종필,박주원,류성기 朝鮮大學校 建設技術硏究所 2004 建設技術硏究 Vol.24 No.2

The construction of roads, bridges and buildings on the ground consisting of frail soft soil or organic soil as it may cause safety problems due to lack of supporting force and over-sinking. It is absolutely necessary to change the form of structures, to decrease internal force by consolidating the base sides of the structures, and to replace frail layers with good-quality materials for enhancement's sake. This paper is designed to make a comparative analysis of safety before and after sand drain methods and sand compaction pile methods were applied On the basis of the results of drilling surveys and indoor tests Sand drain construction methods are introduced to tackle 10-meter-deep frail layers. In case drain intervals are 2.0m ~ 3.5m wide when the construction method reaches 90% of consolidation degrees, 79 months ~ 74 months can be expected in terms of shortened time, respectively. If drain interval drops, the period when 90% of consolidation degrees are reached can be reduced by 2 percent. 2.7 meter-deep banking can be done on the raw soil in case the rate of standard safety against activity destruction stands at 1.25. However, in case four-stage banking is made, 6.8 meter-deep banking is made possible, and in case sand compaction pile construction methods are simultaneously used along with stage-based banking, the maximum baking can be 9.8 meters high ~ 9.0 meters high when drain intervals are 1.8 meters wide ~ 2.2 meters wide, respectively.

偏載荷重을 받는 軟弱地盤의 沈下擧動에 관한 硏究

安鍾弼,曺基鶴 조선대학교 국토개발연구소 1990 국토개발연구 Vol.10 No.1

When unsymmetrical surcharges were activated in the model soils of the 4 kinds of soft soils that are different from the undrained shear strength, cohesive force, it was analyzed and compared, the logical value and measuring value in the statement of settlement, maximum settlement and critical surcharge with the increasing of cohesive force. It was showed that with the increasing of the soil thickness and cohesive force, maximum settlement was inclined between the surcharge between the surcharge breadth of the 0.4B from the boundary and increased linearly, and experimental value was larger than the calculated value when the maximum settlement, C=0.08kg/㎠, critical surcharge and under the same surcharge conditions, cohesive force and settlement was inversed the ratio.

터널굴착시의 지반붕괴에 대한 사례분석

안종필,김석재 朝鮮大學校 建設技術硏究所 2001 建設技術硏究 Vol.21 No.1

Tunnel can defined as "The structure having an underground space that is made by aim and use in the underground" in a broad sense and "The consecutive space, the underground pathway, having an entrance and an exit. For instance, the specific sample of a tunnel are a general way and the tunnel of a rail road Tunnel has been made from long time ago. Therefore, the technique of excavation are incredibly developing, so we can excavate everywhere. However, a sufficient study about the basic theory for designing a tunnel isn't accomplished, because the technique of excavation is based on field experience, so, tunnel is called "undergone engineering. "Furthermore, it's definitely possible in the field of structural engineering to do quantitative analysis and design by using several formulas and programs and putting bearing capacity, condition of load and condition of pressure of soil into the formulas. However the side of choosing analytic tends to be qualitative analysis instead of quantitative analysis because of the difficulty of elucidation, even though it's certain that the shotcrete and rockbolt as a principal support are playing very important roles to make good stability of tunnel The load working on tunnel is changeable by the mature of various earth around a tunnel or shape and size of a tunnel, other factors that make a load on tunnel changeable are not only the dynamic nature of earth, but also geographical features, the method of excavation and so on. However, the tunnel must be made in spit of very complicated surroundings of earth around the tunnel. Finally, we already presented the examples of the collapse of the tunnel and searched a countermeasure by considering the' problems in this study, so we must develop the technique of the basic theory about designing, the tunnel by using the field experience.

파압과 토압을 받는 호안구조물의 안정해석

안종필,박주원 조선대학교 국토개발연구소 1996 국토개발연구 Vol.16 No.1

The time seems to have come when we should pay more attention to the land extention by reclamation of coast. This study is a practical treatise on the stability analysis of revetment structures. For illustrative purposes, the attention of the stability analysis to a revetment structure considered four examples. As a result of stability analysis the safety factor of cap concrete sliding came out as a sequence that the slope revetment with T.T.P block is beggest among all types and is influenced by rigidity of covered materal and slow incline of slope. The safety factor of straight slope sliding and circular sliding failure came out as a sequence that the slope reetment with rubbles is biggest among all type and is influenced by slow incline of slope and increased rigidity of covered materal. The safety factor of oveturnning and bearing capacity came out as a sequence that the slope revetment is bigger than the vertical type and is influenced by slow incline of slope and increased width of structure. In a design for revetment structure, it has to be a planned by a comparative analysis of each safety factor and the merits or demerits.

함수량이 다른 오염지반의 지지력 결정

안종필,박경호,백현 朝鮮大學校 建設技術硏究所 1999 建設技術硏究 Vol.19 No.1

This study, investigates the existing theoretical backgrounds in order to examine the behavior of lateral flow owing to the plasticity of soils when unsymmetrical surcharge is worked on polluted soils by the increase of water content, compares and analyzes the results measured through model tests. Unsymmetrical surcharge is increased at regular intervals to soil tank made up the polluted soils and then the amounts of settlement, lateral displacement and upheaval are observed. Critical surcharge was decided q_(cr)=3.42 C_(u) similar to those had proposed Terzaghi and JHI, and the value of ultimate capacity was decided q_(ult)=7.71 C_(u) similar to that of Tschebotarioff and JHI

오염된 연약지반의 변위량 분포에 관한 연구

안종필,박상범 朝鮮大學校 建設技術硏究所 1998 建設技術硏究 Vol.18 No.2

This study investigates the existing theoretical backgrounds in order to examine the behavior of lateral flow according to the plasticity of soils when unsymmetrical surcharge is worked on polluted soils by the increase of water content and compares and analyzes the results measured through model tests. Model tests are carried out by these : soil tank, bearing frame and bearing plate are made, the water content is soil tank was gradually by increasing ground soils in natural ground of soils and polluted material, unsymmetrical surcharge is increased at regular intervals and then the amounts of settlement, lateral displacement and upheaval are abserved. As the result of model tests, the amount of settlement had a tendency to occur transferring from the left boundary line to the free end of bearing plate, the amount of lateral displacement is occurred concentratively in the range of (0~2/3)H of the thickness of soil layer and that of upheaval soil tank a tendency to transfer from the right boundary line to the ground surface of the free layer of bearing plate.

암반사면의 안정성 검토에 관한 연구

안종필,박주원,오수동 朝鮮大學校 建設技術硏究所 1999 建設技術硏究 Vol.19 No.3

In general the evaluation process of rock slope stability is an ambiguous system which is made up of ideas subjected to practical experience of an expert. This paper aims to propose more effective methods that helps engineers to evaluate the stability of rock slope by using RMR(Rock Mass Rating for the Geomechanics Classification) and Stereo-graphic Projection and Fuzzy Approximate Reasoning Concept. The result of this paper is that a rational evaluation of rock slope stability and countermeasures can be achieved through RMR and Stereo-graphic Projection and Fuzzy Approximate Reasoning Concept.

연약한 점성토 지반의 지지력 결정에 관한 연구

안종필,박상범,김규덕 朝鮮大學校 建設技術硏究所 2004 建設技術硏究 Vol.24 No.2

To find out the variation of bearing capacity due to the plasticity of soils in case of working the unsymmetrical surcharge of ML, CL, and CH, the existing theoretic expression were investigated and were compared with a series of test results The critical surcharge of soft soils was found as q_(cr)=4.22C_(u) in ML, which is slightly larger than the existing expression, but similar to Darragh's expression. The critical surcharge in CL was found as q_(cr)=3.21C_(u), which is the value between JHI and Jaky and in CH was found as qcr=2.60C_(u), which is a the value between Tachebotarioff and Meyerhof. The ultimate bearing capacity of soft soils was found as q_(uIt) = 11.19C_(u) in ML, which was significantly larger than the existing expression. The ultimate bearing capacity of CL was found as q_(ult)=8.41C_(u), which was slightly bigger than the existing expression, but is close to Meyerhof's expression. The ultimate bearing capacity in CH was found as q_(uIt) =4.73C_(u), which is similar to Parndtl's expression.

매립지반의 활용에 따른 문제점에 관한 사례연구

안종필,김건국,박경호 朝鮮大學校 建設技術硏究所 1998 建設技術硏究 Vol.18 No.1

Recently, there will be need to make up construction site on the reclamation ground in considering effective using the small country and expansion of urban site. therefore, there is coming many troubles such as effluence of seepage-out water and differential settlement as constructional structure is made on the soft reclamation ground. This study, examined behavior of foundation, property and behavior of pollution matter and the stable term of reclamation ground when reclamation ground is used to construction site, indicate that there are necessary fact for maintenance-management to investigate 10 case of reclamation construction for the analysis of troubles and their cause. Usually, the reclamation ground is constructing on the soft soils and lubricate action of pollution matter cause the lateral flow pressure to foundation pile. if there were considered to differential settlement pipe-line-arrangement of underground structure must be constructed with flexible joint and reclamation will be required to aseismic design as the shearing force of reclamation ground is suddenly decreased by vibration owing to construction property

연약지반중의 흙막이구조물의 거동해석에 관한 연구

안종필,기완서,오영신 조선대학교 국토개발연구소 1997 국토개발연구 Vol.17 No.1

Recently, a rapid economical development and industrialization require large amount of land of industrial estate and expansion of citis. Therefore the construction of large and deep basements takes place in built up areas where the braced excavation for earth retaining structures causes many problems such as settlement and damages of nearby buildings and underground utilities. This study deals with the behavior of the retaining earth structures and the ground movement around it based on the measuring results which were obtained from the two ground sites. The results of elasto-plastic wall design program involving the effect of lateral flow pressure showed a good agreement with the output of finite difference computer program which covers the behavior of wall as the ground movement around it.