Pile Method Research Articles

High-resolution spectral-element computation of underwater noises due to offshore piling

Offshore piling has been effective in building foundations of offshore structures, such as wind turbines, bridges, and oil rigs. Despite such merits, underwater noise due to offshore piling is considered to be its critical setback. Pile driving creates a high-level underwater sound that harms marine ecosystems. There have been studies that successfully predicted these noises by using numerical methods, for example, Finite Element Method (FEM). However, there has been no FEM study that considers anti-symmetric irregular domains and complex bathymetry to compute underwater noises in the high-frequency range (>1000 Hz) due to expensive computational costs of FEM. To bridge the gap, this work attempts to explore a novel, powerful simulation tool to efficiently obtain offshore piling noises in complex settings and in the high-frequency range. We adopted and modified an open-source large-scale parallel Spectral Element Method (SEM) wave simulator, SPECFEM3D. SEM is known to be much more efficient than FEM for wave propagation analysis problem of a very large number of elements and time steps without compromising accuracy. Our computational method can be used for prediction of offshore piling underwater noise and investigating novel piling methods, such as optimized shapes of piles or air bubbles curtains to mitigate underwater noise.

ANALISA DAYA DUKUNG TIANG PANCANG STATIS DAN DINAMIS PADA BENDUNGAN GERAK SEMBAYAT GRESIK

In general, foundation is defined as the underground building that continues the load from the weight of the building itself and fromthe external load that works at the buildi ng to the ground around it. Carrying capacity analysis of pile is needed to get the planning of foundation that meetsthe requirements. There are many calculation methods used to analyze the carrying capacity of the pile, but it needs to consider which method is more fulfilling from the data in the field, for that, it needs carrying capacity analysis of several methods based on field data using sondir data and compared to one another to obtain more realistic results. Capacity analysis method of pile on the construction of Dams Motion in Sembayat Gresik uses static and dynamic methods. In the dynamic method, it use several methods, those are Hiley equation, Wika Method, ENR method, Eytelwein Method, Navy-Mc.Kay Method, and Michigan State Highway of Commission Method. While in the static method, it uses Luciano Dacourt Method. From the analysis of the static pile carrying capacity obtained the result that pile carrying capacity calculation of Luciano Dacourt Method is smaller, pull Q permitted 15.25 tons and maximum press Q permitted 41.55 tons compared with the calculation method by using kalendering result of Eytelwein Method. In Eytelwein Method, the minimum pile carrying capacity is 61.566 tons of calculations in GW 1.

Performance of constructing a double-deck subway station by combining the shield method and cavern–pile method

A method of constructing a double-deck subway station by combining two parallel shield tunnels and the cavern–pile method is presented. Taking the practical engineering of the Beijing subway as the background, numerical simulations were carried out to study enlarging construction. Mechanical and deformed performances for opening segments, important nodes, and main components of the station structure were investigated. Subsequently, a comparative analysis was performed to investigate the effects of side piles. Finally, an economic investigation was conducted to validate the practicability of the present method. This paper systematically demonstrates the applicability of the proposed method through a three-dimensional numerical simulation. The results show that it is safe and feasible to create a double-deck subway station by enlarging two parallel shield tunnels using the cavern–pile method.

Immersed tunnel foundation on marine clay improved by sand compaction piles

ABSTRACTThe sand compaction pile (SCP) method can be applied to soft marine clay ground that is a reinforcement of composite ground consisting of compacted sand piles and surrounding clay. The application of SCP method in the immersed tunnel of Hong Kong–Zhuhai–Macao Bridge verify SCP method is a robust solution to limit the total settlement and differential longitudinal settlement and to promote smooth transition from immersed tunnel to artificial island. The SCP method has significant settlement reduction effect on marine clay. The SCPs can also function as a drainage path to accelerate the consolidation process in marine clay. It is also found that the consolidation rate of SCP-improved ground is delayed compared with that predicted program which is most probably because of the soil disturbance effect during the installation of SCPs.

Several Conclusions from Standard Test Method for Piles Under Static Axial Compressive Load

Based on test constructed on steel pile on a container terminal, the writer introduces the test method for steel pile under static axial compressive load, and analysis the data received form the test. Inadditional, the writer also gives some advices on piles test under static axial compressive load.

New Method of Performing Soil Tests Using Multisectional Piles

A critical analysis is made of a method that uses piles to perform soil tests (Osterberg method) for the action of impressing loads. An ONLY-DOWN method of testing full-scale multisectional piles is proposed. This method makes testing more reliable and carrying-capacity determination more accurate, which the investigations performed attest.

Results of Laboratory Tests of the Filtration Characteristics of Clay-Cement Concrete

Laboratory studies of the filtration characteristics of clay-cement concrete materials for constructing filtering diaphragms of earth dams by the method of secant piles are reported. Areas for further study aimed at improving the quality of construction, increasing operational safety, and developing a standards base for the design, construction, and operation of these systems are discussed.

Bearing Capacity Characteristics of Steel Pipe Piles with Wings installed in Soil Cement Column

The steel pipe piles with wings installed in soil cement developed in Japan and Vietnam are composite foundation piles made of steel pipes with wings with foundation improvement pillars in soil cement and spiral wings attached to the shaft intermittently. This composite pile has large vertical and horizontal bearing capacities and is a construction method of foundation piles with consideration of environments with little surplus soil, using steel pipes with small diameters. In this study, several full scale loading tests on steel pipe pile with wings installed in soil cement column are presented, and bearing capacity of the composite pile is studied. Especially, combination effect of soil cement column and steel pipe with wings on bearing capacity performance are discussed. Threedimensional elasto-plastic finite element analysis based on the results of loading tests to help understand this composite pile’s mechanical characteristics is also performed.

An improved instrumentation method for PHC piles

This paper describes an instrumentation method to study the behaviour of prestressed high-strength concrete pipe piles (PHC piles) under working static and high-speed-train-induced cyclic loads. The instrumentation method refers to bond resistance-type strain gauges with steel plate inserts that are pre-installed in PHC piles during fabrication. To verify the feasibility of the instrumentation method, three instrumented PHC piles were tested in situ. The test results indicate that the proposed instrumentation method is inexpensive, reliable and promising for cyclic loading. More importantly, the method does not alter the load transfer mechanism of PHC piles. The survival rate of the resistance-type strain gauges installed on the tested piles was found to be higher than 90%. The cumulative settlements induced by high-speed-train-induced cyclic loads were significantly lower than those under working static loads (about 11·5% only), so may be practically neglected when assessing total or post-construction settlement. The unit shaft resistances decreased in clay layers (upper portion of the piles), but increased in sand layers (lower portion of the piles) up to 0·4 million loading cycles. The results from this study provide important technical information for the design of pile foundations supporting high-speed railway bridges.

Axial Resistance of Closed-Ended Steel-Pipe Piles Driven in Multilayered Soil

AbstractIn order to better understand the response of driven, closed-ended, pipe piles subjected to axial loads and examine the performance of existing pile design methods, static and dynamic load tests were performed on a closed-ended steel pipe pile driven in a multilayered soil profile. The test pile was fully instrumented with electrical-resistance and vibrating-wire strain gauges, which enabled the determination of residual loads before sensors were reset and load-transfer curves for all loads applied at the pile head during the static load test. The ultimate base and limit shaft resistances of the test pile measured in the static load test and estimated from dynamic load tests are compared with estimates made using several cone penetration test-based (CPT-based) and property-based pile design methods. Two additional case histories are used to verify these design methods, most of which produce satisfactory estimates of pile resistance.

Winkler load-transfer analysis for laterally loaded piles

The Winkler modulus for a vertical beam buried in elastic soil is reassessed for the problem of a horizontal loaded pile in the framework of linear elasticity. By matching the integral solution in elastic continuum and the expression with the elastic Winkler modulus, the subgrade modulus of an infinitely long pile embedded into elastic space is obtained first. Then the influence of embedment depth and pile rigidity on the subgrade modulus is evaluated by virtue of Mindlin’s and Kelvin’s solutions, which gives the variation of the Winkler spring stiffness along the pile length. Comparison of the results by the present method for single piles in homogeneous and nonhomogeneous soils has shown good agreement with those obtained from the more rigorous elastic continuum solutions and boundary element method, which also revealed the disadvantage of the conventional Winkler expression in evaluating the displacement of the pile. Finally, the present method is used to analyze the pile–soil–pile interaction of a pile group, which also shows good agreement with the finite element method and the elastic continuum method, and proves the feasibility of extending the active subgrade modulus into the realm of the horizontal loaded pile group.

New type sand compaction pile method for densification of liquefiable ground underneath existing structure

The 2011 Great East Japan Earthquake caused severe damage to infrastructures due to liquefaction, in which many embankments failed with large settlement and slope failure. Sand Compaction Pile method is one of the typical ground improvement methods to densify the ground by installing compacted sand piles into ground. This method has been often applied to mitigate the liquefaction. However, current SCP method of constructing sand piles in vertical direction is not able to densify ground underneath an existing structure. For applying the method to an existing structure, a new type of SCP method was recently developed where in compacted sand columns can be constructed in any direction. This paper briefly introduces the new type of SCP method and the effectiveness of local densification by numerical analysis. In this manuscript, a series of numerical analyses were conducted to evaluate the effect of shape and location of SCP improved zone on the dynamic response of embankment. This paper describes the numerical analyses as well as the development, machinery and procedure of the technique, and emphasizes the uniqueness and effectiveness of the technique for preventing liquefaction for new and existing structures.

CPT-correlated design method of open-ended concrete pipe pile

An improved cone penetration test (CPT)-correlated design method is proposed for open-ended prestressed high-strength concrete pipe piles. The method takes the effects of compaction, plugging and friction fatigue into consideration. The evaluation proposal for shaft resistance introduces three parameters of stress reduction factor, compaction sensing coefficient and friction fatigue coefficient with their values addressed. The base resistance is divided into two parts of pile wall resistance and plug capacity, and is expressed in terms of the incremental filling ratio of the soil plug. The ratios of shaft and base resistance to CPT cone resistance, as well as the influence zone for end bearing, are determined. The rationality of this method is tested by comparing the calculated values with the results measured in field tests.

Inactivation of Infectious Bursal Disease Virus Through Composting of Litter from Poultry Houses.

Very virulent infectious bursal disease virus (vvIBDV) was diagnosed in a pullet farm in Washington in 2014. Infectious bursal disease virus is resistant to many environmental stresses and often persists on farms for months. There have been conflicting reports as to whether composting can destroy vvIBDV in the manure. This project investigated the composting of litter from the affected house using an aerated static pile to inactivate the virus. Two weeks before the affected pullet flocks were moved to the layer house, specific-pathogen-free (SPF) birds were placed in the barns. Ten days after they were placed, three SPF birds died and were positive for vvIBDV. Thirty percent of the SPF birds were positive for vvIBDV. After the pullets were moved, at 20 wk of age, the litter in the house was composted using the aerated static pile method. The pile was maintained at above 55 C for 4 wk. After this time, 30 additional SPF birds were placed on the composted material. Two weeks later, the birds were healthy and there was no evidence of vvIBDV. The subsequent pullet flock did not break with vvIBDV. These results demonstrate that this composting method can be used to decontaminate the litter from vvIBDV and help prevent the spread of vvIBDV.

An efficient approach for assessing the seismic soil structure interaction effect for the asymmetrical pile group

All of the civil engineering structures involve some type of structural element which is in direct contact with soil. To estimate the accurate response of the superstructure it is necessary to consider the response of the soil supporting structure, and is well explained in the soil structure interaction analysis. Many attempts have been made to model the SSI problem numerically; however the soil nonlinearity, foundation interfaces and boundary conditions make the problem more complex and computationally costlier. To overcome this problem the attempt has been made to optimize the computational efficiency by applying the equivalent pier method for the deep foundation system. In this research paper the L-shape 11 storey building supported by a pile foundation with homogeneous local soil condition is analyzed for dynamic loading including the SSI effect. The significance of the SSI effect has been studied by comparing the responses of the system for fixed base and flexible base condition. A new approach has been proposed to provide simplicity in SSI modeling and reduce the computational cost (both memory and time wise). The approach includes the applicability of the equivalent pier method for the asymmetrical pile groups system, including SSI effect of the pile foundation system. The approach is validated for group effect and found that equivalent pile method can successfully be adopted and helps to reduce the computational cost of SSI problem. To understand the applicability of EPM approach, the parametric study has been carried out for different input of earthquakes and soil types. In accordance with this the three distinct earthquakes, including 1995 Chamba (M = 4.9), 1999 Uttarkashi (M = 6.9) and 2001 Bhuj (M = 7.7) and soil types including cohesive, cohesionless and C-Phi soils have been considered for SSI analysis. The study observed that, earthquake magnitude and soil type shows the major impact on the response of the SSI system.

Control of floor heaves with steel pile in gob-side entry retaining

A new approach named as steel pile method is innovatively proposed in this study to control severe floor heaves in gob-side entry retaining. It is required that the steel piles be installed in the floor corners with a certain interval before the influence of the dynamic pressure induced by current panel extraction. Using numerical simulation and theoretical analysis, this study investigated the interaction between the steel piles and the floor rocks during the service life of the steel piles, and revealed the mechanism of the steel piles in controlling floor heaves. The effect of the steel pile parameters on the control of floor heaves was presented and elaborated. It is found that the effectiveness of the steel piles in controlling floor heaves can be enhanced with greater installed dip angle, longer length and smaller interval of the steel piles. Compared with traditional methods, e.g., using floor anchor bolts and floor restoration, the advantages using steel pile were successfully defined in terms of controlling effect and economic benefits. It is hoped that the proposed method can contribute to the development of gob-side entry retaining technique.

계면활성제계 그라우트를 활용한 흙막이 벽체공법(CIP)의 현장 적용성 평가

지하수위의 영향을 받는 지반에 대하여 터파기를 실시할 경우 차수문제를 해결하기 위한 방법으로 현장타설말뚝 공법인 CIP (Cast-In-Place Pile) 공법이 보편적으로 사용되고 있다. 그러나 CIP 공법은 말뚝간 연결성이 좋지 않아 많은 경우 차수에 대한 별도의 처리를 필요로 한다. 본 연구에서는 수중불분리성과 침투성을 향상시켜주는 계면활성제(Hi-FA)를 활용한 그라우트를 사용하여 기존 CIP 공법 대비 보조차수 공법의 필요성을 최소화한 새로운 개념의 흙막이 공법(H-CIP)을 제시하고, 이 공법의 현장 적용성에 대하여 검토하였다. 현장 검증실험을 위하여 동일한 지반조건에 대하여 H-CIP 공법과 기존 CIP 공법으로 각각 차수벽을 시공하고, 성능검증을 위한 현장시험 및 실내시험을 수행하였다. 현장 실험결과 새로 제안된 H-CIP 공법은 기존 CIP 공법에 비하여 현장 차수능과 강도가 우수한 것으로 나타났다. In case of underground construction affected by groundwater, CIP (Cast-In-Place Pile) method is generally used to resolve the geo-hydraulic problem. However, as this method has poor connectivity between piles, an auxiliary method for cut-off is needed in many cases. In this study, a new concept earth retaining wall method (H-CIP) with no auxiliary method, by using surfactant grout (Hi-FA) which improves antiwashout and infiltration ability, is introduced, and its field applicability is evaluated. CIP and H-CIP piles were installed with same ground conditions, and field and laboratory tests were conducted to verify the performance. As results, newly contrived H-CIP method shows higher field performance for cut-off and strength than conventional CIP method.

回転貫入により施工される羽根付き杭の周辺地盤の土性変化と水平抵抗特性

A rotary press-in pile with wings has advantages to get large vertical bearing capacity for its pile diameter and to reduce the amount of soil excavated for its installation. On the other hand, it has been concerned that the rotary pile might cause weakening of the soil around the rotary pile. Even in the case of clay, it has not been confirmed that such weakening of the surrounding soil would be caused by peripheral soil displacement during pile installation and/or the passage of pile wings. In this paper, a series of experiments was performed to grasp the behavior of a rotary press-in pile horizontally loaded, and the property changes of surrounding soil by installing a rotary press-in pile with wings. In the experiments, the execution of pile installation was managed with constantly maintaining the ratio of s/p in the range of 1.0±0.1, where s is the penetration length of pile rotated by one revolution and p is the helical pitch of its pile wing. The experiments were carried out at two different sites, where one was the site depositing an alluvium clay layer and the other with a diluvial loam layer. In the experiments, in order to investigate the properties of soil around a pile, the measurements of bulk density and water content were conducted for soil samples taken from the vicinity of the pile shaft with specially equipped apparatus. And also, the one dimensional consolidation test, and the tri-axial compression test were performed for samples taken in the vicinity of the pile were performed. The lateral loading tests, apparatus of one of which was directly equipped with pile shaft and the other of which was normal test, were carried out. In order to compare the differences in the pile installation methods, the laterally loading tests for the pile installed by rotation method and the buried pile were carried out. As a result of this study, the conclusions are as follows. 1) In the soil around a rotary press-in pile with wings, density increase and stiffness decrease were caused by soil displacement and wing passage. 2) The range where soil density increases depends on the compressibility of soil. 3) The stiffness decrease of the soil in the vicinity of pile is more strongly affected by soil displacement than by wing passage. 4) The installation method of the rotary pile constantly maintaining s/p can provide appropriate installation without the occurrence of void around the wing although there seemed the gap between the pile shaft and the ground in any case. 5) The coefficient of horizontal subgrade reaction for the rotary pile with wings became 0.54-0.74 times as large as that for the buried pile due to the gap between pile shaft and ground, and the stiffness decrease of the soil in the vicinity of the pile.

Bearing Capacity Estimation of Bridge Piles Using the Impulse Transient Response Method

A bearing capacity estimation method for bridge piles was developed. In this method, the pulse echo test was used to select the intact piles; the dynamic stiffness was obtained by the impulse transient response test. A total of 680 bridge piles were tested, and their capacities were estimated. Finally, core drilling analysis was used to check the reliability of this method. The results show that, for intact piles, an obvious positive correlation exits between the dynamic stiffness and bearing capacity of the piles. The core drilling analysis proved that the estimation method was reliable.

매입말뚝공법의 충전재료로 사용되는 시멘트밀크의 공학적 특성

In this study, engineering property tests were conducted for cement milk used as a filling materials in the bored piles method. For this purpose, various water/cement ratio specimens were produced on the basis of standard specimen specified in highway corporation specifications. The unconfined compressive strength, point load strength, elasticity modulus, poisson`s ratio test was performed according to the age. As a test result, injection height for productions of cement milk specimens was defined ratios. Correlation coefficient K of the unconfined compressive strength and point load strength were $K_7