Peck Method Research Articles

Analisis Penurunan Muka Tanah (Subsidens) Menggunakan Metode Empirik Di Terowongan Penstock Sta 10+150 PLTA Kerinci Merangin, Kabupaten Kerinci, Provinsi Jambi.

Subsidence analysis in this study was carried out in the Kerinci Merangin hydropower pentstock tunnel construction sta 10+150. The depth of the tunnel at the study site ranges from ± 35 m so that it is included in the shallow tunnel category with the rock at the face of tunnel, namely slate (foliated metamorphic rock) with rock mass conditions is jointed rock with an RMR value of around 23. Predicting subsidence in this study was conducted to assess and determine recommendation due to land subsidence risk based on SNI 8460:2017. Calculation of subsidence values uses the empirical Peck method (Peck, 1969) using primary data in the form of coordinates based on sta location, identification of rock masses and tunnel geometry while secondary data in the form of contour maps is intended to determine the depth of the tunnel. Calculation of subsidence using the peck method requires an inclination point (i) based on the recommendation of Mair (1993), and the land subsidence ratio VL is obtained from the table of the results of Goldsapand's research (1993). Based on the research results, it is known that the maximum subsidence value is 0.97 mm and is right at the center of the tunnel. Furthermore, the value of i or the inflection point is 17.5 m from the tunnel axis with a subsidence value of 0.11 mm and the maximum influence area is at a distance of 20.6 m from the tunnel axis. Based on the SNI 8460: 2017 table, the subsidence in the study area is included in category 1 with recommendations

Practice makes perfect: Approaching Chinese state entrepreneurialism conjuncturally

This commentary argues that the practicability and viability of conjunctural analysis as a method can only be assessed and developed through collective efforts at stress-testing. I draw on key elements of Peck's method to offer a reflexive account considering the contours of a conjunctural analysis of Chinese state entrepreneurialism. I show how conjunctural analysis allows me to identify and understand the multiplex causality of China's shift in approach to urban redevelopment, and to develop relevant midlevel concepts which help to revise and broaden understandings of state entrepreneurialism. Rather than a one-to-one mapping between case and concept, conjunctural analysis has the potential to allow researchers to theorise geographical phenomena across time and space, where multiple lines of analyses and conceptualisation can enable horizontal and vertical theorisation, offering erstwhile obfuscated analytical insight and theoretical generativity.

Modified Peck method of evaluating tunnelling-induced ground movements based on measured data

Modified Peck method of evaluating tunnelling-induced ground movements based on measured data

A New Modified Peck Formula for Predicting the Surface Settlement Based on Stochastic Medium Theory

Peck method and stochastic medium method are the two most commonly used methods to estimate surface settlement caused by tunnel excavation. However, the Peck method was not suitable for a shallow‐buried tunnel, and the calculation process of the stochastic medium theory was complicated. To solve this problem, in this paper, a simple and accurate prediction approach for surface settlement was obtained by improving the Peck method based on the basic idea of stochastic medium theory. In detail, the over‐excavation area of the tunnel was divided into n independent units, and the surface settlement caused by the collapse of each unit was calculated, respectively. Then, the total surface settlement can be obtained by superimposing surface settlement induced by each unit. Taking the shallow‐buried section of Mulingguan tunnel entrance as a case, the surface settlement calculated by the modified Peck formula and original Peck formula was compared with the observed data, respectively. The comparison results indicated that the surface settlement calculated by the modified Peck formula is closer to the observed data than that calculated by the original Peck formula in the calculation process of surface settlement of shallow‐buried tunnel. The table of recommendation for the number of units can be obtained by a discussion of reasonable n values. Finally, the difference between the original Peck formula and the modified Peck formula was analysed, and the results showed that the change rule of the surface settlement is consistent under the tunnel depth, internal friction angle, and ground loss of the tunnel. However, the calculation error of the surface settlements calculated by the original Peck formula is more significant than that calculated by modified Peck formula under the tunnel diameter ratio being less than 1.75. The modified Peck formula is more suitable for calculating the surface settlement under internal angle friction being less than 20° or greater than 40°. The research results expand the scope of application of the original Peck formula and enrich the calculation approach of surface settlement induced by underground excavation in tunnel construction.

Seismic behavior and design of strutted diaphragm walls in sand

In this paper, the seismic behavior and design of strutted diaphragm wall are evaluated in a dry cohesionless soil. The method of ACI 318 code for designing wall and also Peck's method under AISC regularization for designing steel strut have been discussed. The results indicated that conventional methods of wall and strut design have an acceptable performance in static condition, but when it is subjected to seismic loads, these methods return the values of bending moment and shear force of wall up to 2.8 times and the axial stress in strut up to 11 times larger than allowable limits.

Countersink accuracy control of thin-wall CFRP/Al stack drilling based on micro peck strategy

The countersink accuracy problem caused by the deformation of thin-wall stacked structures is common in aircraft manufacturing, particularly for stacks with low stiffness. In the countersinking process of carbon fiber reinforced plastic (CFRP) and aluminum (Al) stacks, the cutting edge is quickly and severely worn due to the hard machinability of CFRP, resulting in the rapid increase of thrust force and then deformation. Focusing on the countersink accuracy control in CFRP/Al stacks, this paper first developed a CFRP countersinking thrust force model that considers tool wear and verified by experiments to help to investigate the stack deformation; then the micro peck strategy with quantitative analysis and theoretical modeling, which aims to decrease deformation and improve countersink accuracy, has been proposed based on the thrust force model and studied for its effectiveness in multivariate simulations and experiments. The research results indicate that both the increase of flank wear land of the tool and the decrease of stiffness of the stacks are the primary factors that undermine the countersink accuracy because they can affect the stack deformation, but using the micro peck strategy will minimize the adverse impact of these factors. The work in this paper includes two advantages: the micro peck method can be applied to the aeronautical manufacture with complex actual machining conditions; the theoretical model enables us to select appropriate peck parameters for the CFRP/Al stack countersinking process.

Determination of Main Influence Angle of Ground Settlement Caused by Xi'an Metro Tunnel Construction

Peck method and Stochastic medium method (SMM) are widely used in the field of ground movement included by urban soft ground tunnelling in China. The determination for the key parameter for SMM is also a problem because of the relative little experience from the engineering application in China. Through discussing the theoretical relationship between Peck method and SMM, Peck method can be regarded as a simplification of SMM where is used in relatively deeper excavation condition, and the method of determination for the key parameter for SMM is suggested. The suggested method are proven and verified by some practical engineering projects. Finally, they can significantly improve the adaptability of SMM in engineering application.

A case study on the behavior of shield tunneling in sandy cobble ground

This study investigates the behavior of shield tunneling based on a complete case record of an excavation in sandy cobble ground. Both numerical and analytical analyses were conducted to estimate the surface displacement along the tunnel axis and the surface-zone affected by the shield tunneling. This paper presents the performance of the Peck method in forecasting the transversal surface settlement trough caused by the shield tunneling in a sandy cobble layer. In particular, this study has made a comparison with the vertical surface displacement monitored during the advancing excavation to the settlements estimated by using the Peck method and by conducting a three-dimensional finite element analysis. The effective measures to provide the necessary face support pressure and to reduce the formation of sinkholes and ground settlements in sandy cobble ground were also investigated and discussed.

腰痛に対する腰部への鍼の刺入深度の違いによる治療効果の相違―ランダム化比較試験―

[Objective] The purpose of this study was to compare the effects of superficial and deep insertion of acupuncture needles in the treatment of patients with low back pain and to search for more effective acupuncture methods. [Methods] A randomized controlled clinical trial was conducted in which 32 patients with low back pain for more than three months of duration were randomly allocated either to a superficial acupuncture group (n = 16) or a deep acupuncture group (n = 16). Treatment was done for the most painful points of the patients. In the superficial insertion group, the needle was only inserted to a depth of 5 mm, whereas in the deep insertion group, the needle was inserted to a depth of about 20 mm, and was manually stimulated (sparrow pecking method) for 20 seconds. Both groups were treated weekly for four weeks. The visual analog scale (VAS) of pain, Roland-Morris Disability Questionnaire (RDQ), and Pain Disability Assessment Scale (PDAS) were used for outcome measurement. [Result] VAS, RDQ and PDAS scores showed significant differences between groups (VAS: p < 0.05, RDQ: p <0.001, PDAS: p < 0.05) in change over time with the deep insertion group having more favorable results than the superficial insertion group. The degree of change from the baseline at the time of each evaluation was calculated and results for the two groups were compared. The deep insertion group was significantly better in tendency to improve directly after the first treatment (p < 0.01), in cumulative effect after repeated treatment (VAS: p = 0.13, RDQ: p < 0.05, PDAS: p < 0.01), and in sustained effect after completion of treatment (VAS: p < 0.05, RDQ: p < 0.01, PDAS: p <0.05). [Discussion and Conclusion] The study showed that deep stimulation is a more effective treatment than superficial stimulation. It is thought that the differences of the effects are due to different influences of the treatments on the pain threshold, muscle blood flow, and muscle tones..

ランダム化比較試験による頚肩部痛に対する鍼治療と局所注射の検討

[Objective] The purpose of this study was to compare the effectiveness of acupuncture and local injection for neck pain. [Methods] A randomized controlled clinical trial was conducted in which 33 patients with neck pain were randomly allocated to either an acupuncture group or a local injection group. For the acupuncture group (n = 16), a stainless steel needle was inserted to depths from 10 to 20 mm and manually stimulated (sparrow pecking method) for 20 seconds. While a 25 gauge needle was inserted to depths from 10 to 20 mm, neovitacain (dibucaine hydrochloride 0.1 percent, sodium salicylate 0.3 percent, calcium bromide 0.2 percent) and neurotropin (a non protein component extracted from the skin of rabbits treated with vaccinia virus) were injected for the local injection groups (n = 17). Both groups received each treatment at the most painful points weekly during four weeks. Primary outcome measurement was intensity of the pain evaluated with a visual analogue scale (VAS). Secondary outcomes were Neck Disability Index (NDI) and a standardized questionnaire of cervical root disease (developed by Tanaka et al. at Tohoku Univ.). The evaluations were independent from the therapists. [Results] The acupuncture group showed better results in all the outcome measurements than those in the local injection group for the effect immediately after the treatment, the effect of sequential treatment and the sustained effect after completion of treatment. [Discussion] The result of this study suggested that acupuncture can become a more useful treatment method compared with local injection. The difference of the effects between two treatment methods may be due to the difference of the mechanism to suppress pain.

Relief of Low Back Pain Immediately after Acupuncture Treatment – a Randomised, Placebo Controlled Trial

The purpose of this study was to examine the immediate effect of single acupuncture stimulation to the most painful point in patients with low back pain. A randomised, evaluator-blinded, sham controlled clinical trial was conducted in which 31 patients with low back pain were randomly allocated to either an acupuncture group (n = 15) or a sham acupuncture group (n = 16). Both acupuncture and sham acupuncture were performed at the most painful point on the lower back of the subjects. For the acupuncture group, a stainless steel needle was inserted to a depth of 20 mm and manually stimulated (sparrow pecking method) for 20 seconds, while for the sham treatment a guide tube without a needle was placed at the point and tapped on the skin. Changes in low back pain were evaluated with a visual analogue scale (VAS) and the Schober test. Participants were also asked if they felt the needling sensation or not. The therapy and the evaluation were independently performed by two different acupuncturists. VAS score and the Schober test score showed significant improvement after treatment as compared with the sham group (P = 0.02, 0.001, respectively). There were no significant differences in the needling sensation between the acupuncture and sham group. These results suggest that acupuncture at the most painful point gives immediate relief of low back pain.

A Remark about Peck's Method in Positive Characteristic

In this short paper, we study Peck’s method in positive characteristic. Curiously enough, the simultaneous approximations this method provides are better than in the real field.

Ground and building settlement due to tunnelling in Hong Kong : R. A. Forth & C. B. B. Thorley, in: Land subsidence. Proc. international symposium, The Hague, 1995,ed F.B.J. Barends & others, (IAHS; Publication, 234), 1995, pp 149–160

Extensive monitoring of the ground and buildings affected by the construction of the Island Line (ISL) of the Mass Transit Railway (MTR) in Hong Kong was carried out between 1982 and 1986. Predictions were based on the Peck method (Peck, 1969) and the monitoring enabled a comparison of prediction and performance to be made. The results suggested that tunnels in completely weathered granite behaved as in Peck's sands (cohesive granular soils) whilst the shallow tunnels in colluvium, alluvium or marine clays behaved like Peck's soft clay. This paper reports the results of some of the monitoring and provides a tunnelling settlement estimate method suitable for Hong Kong.

Visual search in the pigeon: hunt and peck method.

Pigeons pecked at small forms displayed on an oscilloscope screen under computer control. The birds were required to find a small o amid varying numbers of x forms. A photocell glued to the bird's beak provided a signal to the computer when the beak approached a form, and the computer recorded the time and target of the response. As in some similar studies with human subjects, erros and reaction times increased with number of x forms displayed. The method appears promising for further studies of search and of other processes related to perception and information-processing in birds.

Settlement of Spread Footings on Sand

Settlement measurements for a large number of footings supported on dune sand are compared to settlement predictions based on standard penetration tests, plate load tests, oedometer tests and triaxial stress path tests. The sand considered in this study has been preloaded by dunes or compacted by vibratory rollers. Good agreement between measurement and prediction is obtained using the procedure suggested by Meyerhof, a modification of the Terzaghi and Peck method, provided that the blow-count is corrected for overburden pressure. Good agreement is also obtained with oedometer and stress path test predictions. Predictions based on plate load tests underestimated measured settlements whereas the conventional correlations between settlement and standard penetration test resistance overestimated measured settlements.