Optimal Anchor Research Articles

Is Allograft Reconstruction of the Medial Ulnar Collateral Ligament of the Elbow a Viable Option for Nonelite Athletes? Outcomes at a Mean of 8 Years.

Background:The rate of elbow medial ulnar collateral ligament (MUCL) injury and surgery continues to rise steadily. While authors have failed to reach a consensus on the optimal graft or anchor configuration for MUCL reconstruction, the vast majority of the literature is focused on the young, elite athlete population utilizing autograft. These studies may not be as applicable for the “weekend warrior” type of patient or for young kids playing on high school leagues or recreationally without the intent or aspiration to participate at an elite level.Purpose:To investigate the clinical outcomes and complication rates of MUCL reconstruction utilizing only allograft sources in nonelite athletes.Study Design:Case series; Level of evidence, 4.Methods:Patient records were retrospectively analyzed for individuals who underwent allograft MUCL reconstruction at a single institution between 2000 and 2016. A total of 25 patients met inclusion criteria as laborers or nonelite (not collegiate or professional) athletes with a minimum of 2 years of postoperative follow-up. A review of the medical records for the included patients was performed to determine survivorship free of reoperation, complications, and clinical outcomes with use of the Summary Outcome Determination (SOD) and Timmerman-Andrews scores. Statistical analysis included a Wilcoxon rank-sum test to compare continuous variables between groups with an alpha level set at .05 for significance. Subgroup analysis included comparing outcome scores based on the allograft type used.Results:Twenty-five patients met all inclusion and exclusion criteria. The mean time to follow-up was 91 months (range, 25-195 months), and the mean age at the time of surgery was 25 years (range, 12-65 years). There were no revision operations for recurrent instability. The mean SOD score was 9 (range, 5-10) at the most recent follow-up, and the Timmerman-Andrews scores averaged 97 (range, 80-100). Three patients underwent subsequent surgical procedures for ulnar neuropathy (n = 2) and contracture (n = 1), and 1 patient underwent surgical intervention for combined ulnar neuropathy and contracture.Conclusion:Allograft MUCL reconstruction in nonelite athletes demonstrates comparable functional scores with many previously reported autograft outcomes in elite athletes. These results may be informative for elbow surgeons who wish to avoid autograft morbidity in common laborers and nonelite athletes with MUCL incompetency.

DUPRFloor: Dynamic Modeling and Floorplanning for Partially Reconfigurable FPGAs

Nowadays, field-programmable gate array (FPGA) devices have been widely used in various fields. However, modules of circuits to be executed on FPGAs are placed within rectangular reconfigurable regions (RRs) with current floorplanners, leading to internal fragments, and lower utilization of resources. To address this, a dynamic description model of RRs and the corresponding floorplanner named dynamic union partial reconfiguration floorplan (DUPRFloor) are proposed in this article. The RR dynamic description modeling adds an anchor within a rectangular RR to reduce internal fragments. In this way, the modeling can represent both rectangular and nonrectangular shapes. Then, to find the optimal anchor, a clipping method is devised by constraining width and height of the candidate region. Finally, the mixed-integer linear programming (MILP) is used to optimize an objective function which considers the resources utilization and communication costs to obtain a desirable floorplanning result. The proposed method has been validated by simulation on three kinds of devices. And experimental results show that reconfigurable resources can be saved as much as 19.16% compared to rectangular modeling method. The DUPRFloor is also validated on the Microelectronics Center of North Carolina standard benchmark data sets. Results show that DUPRFloor can reduce 18.65% global wire length at most with almost the same execution time compared to state-of-the-art algorithms. Our approach is tested on a FPGA implemented software-defined radio (SDR) and reduced 29.41% wasted configurable frames, and to the overall design, 2% configurable frames are saved at most.

Autonomous pavement distress detection using ground penetrating radar and region-based deep learning

• A Faster R-ConvNet was developed for pavement distress detection. • The optimal anchor sizes and ratio were determined. • The performance of the optimal Faster R-ConvNet were verified. Many data processing technologies have been utilized for pavement distress detection (e.g., reflection cracks, water-damage pits, and uneven settlements) using ground penetrating radar (GPR). However, the various real-world conditions have resulted in challenges of the accuracy and generalization ability of these techniques. To overcome these challenges, we proposed a deep-learning method, called faster region convolutional neural network (Faster R-ConvNet), to complete the task. The 30 Faster R-ConvNets were trained, validated, and tested using 2,557, 614, and 614 GPR images, respectively. The optimal anchor size and ratio were determined based on the validation results. The stability, superiority, real-time of the optimal Faster R-ConvNet were verified based on the test results. The results demonstrated that the optimal Faster R-ConvNet achieved 89.13% precision and 86.24% IoU. The stability of the model in different pavement structures was desirable. The comparative study indicated that the optimal Faster R-ConvNet outperformed other supervised learning methods in distress detection. Additionally, a real-time detection using optimal Faster R-ConvNet was conducted with acceptable accuracy.

Anchorage strength and ductility at various loading conditions

Article shows results of anchor pullout tests for two types of anchors: bent foundation anchor bolt and torque-controlled undercut anchor. Effective embedment depth is determined during research for bent anchors 16, 24 and 36 mm in diameter. Tests were carried out for 37 specimens with different embedment depth in a range from 150 to 650 mm. Load-displacement diagrams for static and cyclic dynamic pullout tests in uncracked and cracked concrete were acquired. Cyclic loading pattern simulated seismic loads. Test results for undercut anchors with diameter of 12, 16 and 20 mm and embedment depth of 125, 190 and 250 mm respectively allowed to estimate the influence of cracks in concrete and cyclic loads on ductility of anchor during pullout tests. It is stated that embedment depth required by regulatory documents for bent anchor bolt is higher than admissible embedment depth acquired in tests as a result of comparative analysis of design and optimal anchor bolt structure.

Parametric Study of the Effect of Ground Anchor on Deep Excavation Stability

Apartment construction is mostly carried out by including deep excavation works. However, excavation causes land instability; hence, the work needs to be done by a particular handler. In some cases, deep excavation is carried out on soft soil, which has a very high level of soil instability; therefore, a specific handling method such as ground anchor is required as an alternative. This study aims to conduct parametric research on the effect of using anchors on the stability of deep excavation. First, anchors of various slopes were modelled while varying the number of anchors up to four pieces. From the results of the study, the requirements representing the most efficient use of anchors were selected, and then various anchor bond lengths were modelled. Finally, the effect of applying various magnitudes of prestress forces to the anchor was determined. All of the models were examined to determine the influence on the stability of the deep excavation by observing the horizontal displacement and the forces that occur on the secant pile. From the analysis results, it can be concluded that the most effective slope angle is 0°. The displacement and forces occurred in the secant piles on the use of two, three, or four anchors has not a significant difference. The application of a higher prestress force on the anchor would yield better results as long as it is not exceeding 200 kN. However, in the case of an apartment building’s plans in Surabaya, the optimal anchor usage was found to be the use of two anchors with a 45° slope, 4.5 m for the first (A) and second (B) anchor bond lengths, 15 m free length anchor, 2.5 m vertical anchor distance, 1.2 m horizontal anchor distance, and the application of 200 kN prestress force.

UWB System for Indoor Positioning and Tracking with Arbitrary Target Orientation, Optimal Anchor Location, and Adaptive NLOS Mitigation

The Ultra-wideband (UWB) system for indoor positioning and tracking with the characteristics of arbitrary target orientation, optimal anchor location, and adaptive non-line-of-sight (NLOS) mitigation characteristics is proposed and implemented by introducing the circularly polarized antenna, the genetic algorithm (GA), and the machine learning method. The time-domain characteristic of the UWB system using the proposed circularly polarized antennas with wide bandwidth and omnidirectional radiation is investigated by transient response. Contrary to UWB system using the conventional linearly polarized antenna, the pulse distortion is insignificant and is verified by the measured antenna performance with high signal fidelity (>0.98) and low standard deviation (STD) of time delay (<; 0.05 ns). By considering the NLOS electromagnetic wave propagation models, the locations of the anchors in the UWB system are effectively optimized by using the proposed GA to minimize the average root-mean-square error (RMSE) of each tag location in the dense multipath area. By optimizing the three anchor locations, the average RMSE of tag location is minimized to 36.72 cm for a 45 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> area with concrete walls and pillars. The adaptive NLOS mitigation is investigated by using and optimizing machine learning models, including deep neural network (DNN), convolutional neural network (CNN) and long short-term memory (LSTM). The three-anchor UWB system for a 45 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> area is established to track an autonomous vehicle in severe NLOS environment by using the proposed circularly polarized antenna combined with the optimized LSTM model, achieving the measured positioning error of 26.1 cm. Moreover, the measured result of 20-30 cm positioning error with concrete walls, pillars and walking humans is demonstrated and analyzed.

Forecasting core inflation: the case of South Africa

ABSTRACT Underlying, or core, inflation is likely the most important variable for monetary policy. It is considered to be the optimal nominal anchor as it is stable, excludes relative price shocks, and reflects underlying trends in the behaviour of price-setters and demand conditions in the economy. Despite its importance, there is sparse literature on estimating and forecasting core inflation in South Africa, with the focus still on measuring it. This paper emphasizes predicting core inflation from time-varying parameter vector autoregressive models (TVP-VARs), factor-augmented VARs (FAVAR), and structural break models using quarterly data from 1981Q1 to 2013Q4. We use mean squared forecast errors (MSFE) and predictive likelihoods to evaluate the forecasts. In general, we find that (i) time-varying parameter models consistently outperform constant coefficient models (ii) small TVP-VARs outperform all other models; (iii) models with heteroscedastic errors do better than models with homoscedastic errors; and (iv) allowing for structural breaks does not improve the predictability of core inflation. Overall, our results imply that additional information on the growth rate of the economy and the interest rate is sufficient to forecast core inflation accurately, but the relationship between these three variables needs to be modelled in a time-varying fashion.

Hole enlarging anchorage technology of surrounding rock of roadway in weakly consolidated formation

Aiming at the problem of surrounding rock deformation control of the roadway in weakly consolidated formation and combined with the calculation method of anchoring force of anchor bolt, this paper analyzes the feasibility of hole enlarging and anchoring and proposes a calculation method for the anchoring force of hole enlarging and anchoring; this paper establishes a simplified mechanics model of cylinder table enlarging, standing circular table enlarging and circular table enlarging with the method of theoretical mechanics and material mechanics and finds after analysis that the anchoring effect is best when the angle between the busbar and the axis of the circular table is θ < 45°. It draws a two-variable function relation curve for the surrounding rock stress σb and the hole enlarging parameters at the supporting region of the enlarged part of the standing circular table and obtains the optimal anchor length L is 130 mm, the optimal hole enlarging angle θ is 15°, and the optimal hole diameter D is 100 mm. It verifies the theoretical analysis results with numerical calculation, and the results show that the theoretical derivation is consistent with the simulation results. The research results make up the inadequacies of the accurate calculation method for the optimal hole enlarging parameters of the surrounding rock hole of roadway in the weakly consolidated formation, and provide a theoretical basis for the popularization and application of the anchoring technology in the roadway support of weakly consolidated formation.

A Simple Algorithm for Solving Ramsey Optimal Policy with Exogenous Forcing Variables

This article presents an algorithm that extends Ljungqvist and Sargent's (2012) dynamic Stackelberg game to the case of dynamic stochastic general equilibrium models including forcing variables. Its first step is the solution of the discounted augmented linear quadratic regulator as in Hansen and Sargent (2007). It then computes the optimal initial anchor of jump variables such as inflation. We demonstrate that it is of no use to compute non-observable Lagrange multipliers for all periods in order to obtain impulse response functions and welfare. The algorithm presented, however, enables the computation of a history-dependent representation of a Ramsey policy rule that can be implemented by policy makers and estimated within a vector auto-regressive model. The policy instruments depend on the lagged values of the policy instruments and of the private sector's predetermined and jump variables. The algorithm is applied on the new-Keynesian Phillips curve as a monetary policy transmission mechanism.

The correlations between the anchor density and the curve correction of adolescent idiopathic scoliosis surgery

BackgroundThe optimal anchor density in adolescent idiopathic scoliosis (AIS) surgery to achieve good curve correction remains unclear. The purpose of the study is to analyze the correlations between three-dimensional curve correction and anchor density in the pedicle screw-based posterior fusion of AIS.MethodsOne hundred and twenty-seven AIS patients receiving primary posterior fusion with pedicle screw instrumentation were retrospectively reviewed. Anchor density (AD) was defined as the screws number per fused spinal segment. The correlations between three-dimensional curve correction radiographic parameters and anchor density were analyzed with subgroup analysis based on different curve types, curve magnitudes, and curve flexibilities. The differences of curve correction parameters between the low-density (AD ≤1.4), middle-density (1.4 < AD ≤1.7) and high-density (AD > 1.7) groups were also calculated. Independent t-test, analysis of variance (ANOVA), and Pearson’s correlation coefficient were used for statistical analysis.ResultsThere were no correlations between the anchor density and the coronal curve correction or apical vertebral rotation (AVR) correction. In the sagittal plane, mild positive correlations existed between anchor density and thoracic kyphosis correction in all patients (r = 0.27, p = 0.002). Subgroup analysis revealed similar mild positive correlations in Lenke 1 (r = 0.31, p = 0.02), Lenke 1–3 (r = 0.27, p = 0.01), small curves (40°-60°, r = 0.38, p < 0.001), and flexible curves (flexibility > 40%, r = 0.34, p = 0.01).There were no differences between low-density (mean 1.31), middle-density (mean 1.55), and high-density (mean 1.83) in terms of coronal or axial curve correction parameters. Low-density group has longer fused level (mean difference 2.14, p = 0.001) and smaller thoracic kyphosis correction (mean difference 9.25°, p = 0.004) than high-density group.ConclusionIn our study, the anchor density was not related to coronal or axial curve corrections. Mild positive correlations with anchor density were found in thoracic kyphosis correction, especially in patients with smaller and flexible curves. Low anchor density with longer fusion level achieves similar curve corrections with middle or high anchor density in adolescent idiopathic scoliosis surgery.

Multi-layer Feature Fusion Network with Atrous Convolution for Pedestrian Detection

In this paper, we present a simple but effective framework K-AFPN that incorporates feature pyramid method for small-size pedestrian detection, fully utilizing the lower-layer detail features and higher-layer semantic features. The method not only enhances the robustness of the features, but also improves the discrimination of the feature maps, achieving competitive accuracy. In addition, atrous convolution is used to optimize the network for high-resolution feature maps, avoiding information loss caused by frequent down or up sampling. On top of the backbone network, K-means algorithm is used to obtain optimal initial anchor base sizes, which reduces computational costs and improves location accuracy. Hence, our method pays more concentration on pedestrians, especially those of relatively small size. Comprehensive experimental results on two classic pedestrian benchmarks illustrate the effectiveness of the proposed approach.

Optimising the dimensions of Suction Embedded Anchors by investigating the opening mechanism

This paper aims to optimise the dimensions of Suction Embedded Anchors (SEAs) by investigating the opening mechanism through numerical large deformation finite element (LDFE) modelling. Consisting of two hinged half-cylindrical flukes, an SEA anchor uses a tactical design to allow the flukes to open under preloading to achieve more bearing area and, thus, a higher holding capacity. However, the applicability and practicability of this anchor depends on the opening process, where a critical dimension is the ratio of the anchor height relative to the diameter. A longer anchor increases both the forces prompting the opening process and the forces resisting it. The initial prompting force is the friction along the flukes and pressure on the wall annulus, while the initial resisting force is the soil pressure on the fluke faces. The LDFE results of this study demonstrate that these two components are in different orders of magnitude. Therefore, increasing the anchor height does not necessarily always increase the holding capacity but can have a detrimental effect on the holding capacity. The optimal anchor height is found to be ∼0.75 times the diameter. The detailed opening process and mechanism are demonstrated in the systematic LDFE analyses presented in this paper.

Proximal Hamstring Repair: A Biomechanical Analysis of Variable Suture Anchor Constructs

Background:Despite an abundance of literature regarding construct strength for a myriad of anchors and anchor configurations in the shoulder, there remains a paucity of biomechanical studies detailing the efficacy of these implants for proximal hamstring repair.Purpose:To biomechanically evaluate the ultimate failure load and failure mechanism of knotless and knotted anchor configurations for hamstring repair.Study Design:Controlled laboratory study.Methods:A total of 17 cadaveric specimens divided into 3 groups composed of intact hamstring tendons as well as 2 different anchor configurations (all-knotted and all-knotless) underwent first cyclic loading and subsequent maximal loading to failure. This protocol entailed a 10-N preload, followed by 100 cycles incrementally applied from 20 to 200 N at a frequency of 0.5 Hz, and ultimately followed by a load to failure with a loading rate of 33 mm/s. The ultimate failure load and mechanism of failure were recorded for each specimen, as was the maximal displacement of each bone-tendon interface subsequent to maximal loading. Analysis of variance was employed to calculate differences in the maximal load to failure as well as the maximal displacement between the 3 study groups. Holm-Sidak post hoc analysis was applied when necessary.Results:The all-knotless suture anchor construct failed at the highest maximal load of the 3 groups (767.18 ± 93.50 N), including that for the intact tendon group (750.58 ± 172.22 N). There was no statistically significant difference between the all-knotless and intact tendon groups; however, there was a statistically significant difference in load to failure when the all-knotless construct was compared with the all-knotted technique (549.56 ± 20.74 N) (P = .024). The most common mode of failure in both repair groups was at the suture-tendon interface, whereas the intact tendon group most frequently failed via avulsion of the tendon from its insertion site.Conclusion:Under biomechanical laboratory testing conditions, proximal hamstring repair using all-knotless suture anchors outperformed the all-knotted suture anchor configuration with regard to elongation during cyclic loading and maximal load to failure. Failure in the all-knotted repair group was at the suture-tendon interface in most cases, whereas the all-knotless construct failed most frequently at the musculotendinous junction.Clinical Relevance:No biomechanical studies have clearly identified the optimal anchor configuration to avert proximal hamstring repair failure. Delineating this ideal suture anchor construct and its strength compared with an intact hamstring tendon may alter the current standards for postoperative rehabilitation, which remain extremely conservative and onerous for these patients.

Outlier Detection and Optimal Anchor Placement for 3-D Underwater Optical Wireless Sensor Network Localization

Location is one of the basic information required for underwater optical wireless sensor networks (UOWSNs) for different purposes such as relating the sensing measurements with precise sensor positions, enabling efficient geographic routing techniques, and sustaining link connectivity between the nodes. Even though various two-dimensional UOWSNs localization methods have been proposed in the past, the directive nature of optical wireless communications and three-dimensional (3D) deployment of sensors require to develop 3D underwater localization methods. Additionally, the localization accuracy of the network strongly depends on the placement of the anchors. Therefore, we propose a robust 3D localization method for partially connected UOWSNs which can accommodate the outliers and optimize the placement of the anchors to improve the localization accuracy. The proposed method formulates the problem of missing pairwise distances and outliers as an optimization problem which is solved through half quadratic minimization. Furthermore, analysis is provided to optimally place the anchors in the network which improves the localization accuracy. The problem of optimal anchor placement is formulated as a combination of Fisher information matrices for the sensor nodes where the condition of D-optimality is satisfied. The numerical results indicate that the proposed method outperforms the literature substantially in the presence of outliers.

Abstract 2267: A novel method for classification of microsatellite instability (MSI) using the Oncomine Tumor Mutation Load assay

Abstract Cancer-associated changes in short tandem repeats (STRs) throughout the genome have been shown to be predictive of response to immunotherapy treatment. Traditional assays efficiently rely on a small number of genomic loci to assign an MSI status, but are only effective in a small number of cancer types. Genome-wide profiling of aberrations in STRs has the potential to reveal a comprehensive signature of MSI and could allow for the association of response with samples that are labeled as microsatellite stable (MSS) by traditional assays.To facilitate the discovery of informative repeat sites across the genome, we have extended the Oncomine Tumor Mutation Load assay* to allow for the detection of variants in STRs. Our method addresses challenges of semiconductor sequencing of long STR elements including indel and partial incorporation signal errors. We developed an algorithm to avoid and correct these errors in flowspace, rather than base space, to ensure accurate signal assessment. Our pipeline is able to determine the optimal anchor locations used to identify the exact position of a repeat sequence within a read and then quantify the size, sequence, and number of reads associated with each allele. An additional complication of accurately quantifying the length of an STR is the increased error rates of the polymerase during DNA amplification. By evaluating the similarity of every loci between tumor and normal pairs of an individual using a metric derived from information theory, we are able to account for both the sequencing and PCR associated noise to robustly identify the genome-wide changes. Furthermore by evaluating a set of 24 MSI-High and 24 MSS samples along with their paired normal samples, we created a novel method to identify a highly informative subset of STR loci. Creating a classifier using only these highly informative loci, we are able to recapitulate the traditional MSI assay with 95% accuracy on these initial samples. This general methodology can be further extended to a model where MSI status is predicted using only the tumor sample, without the need for a control from the same individual. Due to the flexibility of this method, we are able to examine an increased number of potentially informative loci and use the total mutation load along with mutation calls in the MMR genes to provide comprehensive, multi-dimensional genomic perspective of samples. While this novel method has been developed and tested on the Oncomine Tumor Mutation Load assay, we have created a novel general approach that can be used on the output of any semiconductor sequencing assay. The extended information derived from individual mutations and the total mutation load, along with STR aberration information allows for a comprehensive evaluation of every sample and promotes the discovery of novel genomic components important for understanding the mechanisms of immune-oncology. *For research use only Citation Format: Aleksandr Pankov, Sameh El-Difrawy, Warren Tom, Jeffrey Conroy, Sean Glenn, Sarabjot Pabla, Carl Morrison, Fiona Hyland, Simon Cawley. A novel method for classification of microsatellite instability (MSI) using the Oncomine Tumor Mutation Load assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2267.

Insights into the Impact of a Membrane-Anchoring Moiety on the Biological Activities of Bivalent Compounds As Potential Neuroprotectants for Alzheimer's Disease.

Bivalent compounds anchoring in different manners to the membrane were designed and biologically characterized to understand the contribution of the anchor moiety to their biological activity as neuroprotectants for Alzheimer's disease. Our results established that the anchor moiety is essential, and we identified a preference for diosgenin, as evidenced by 17MD. Studies in primary neurons and mouse brain mitochondria also identified 17MD as exhibiting activity on neuritic outgrowth and the state 3 oxidative rate of glutamate while preserving the coupling capacity of the mitochondria. Significantly, our studies demonstrated that the integrated bivalent structure is essential to the observed biological activities. Further studies employing bivalent compounds as probes in a model membrane also revealed the influence of the anchor moiety on how they interact with the membrane. Collectively, our results suggest diosgenin to be an optimal anchor moiety, providing bivalent compounds with promising pharmacology that have potential applications for Alzheimer's disease.

Drained monotonic and cyclic capacity of a dynamically installed plate anchor in sand

The emergence of commercial offshore floating renewable energy devices that are expected to be deployed in large integrated arrays in relatively shallow water requires anchor types that are suited to sandy seabeds. This paper considers centrifuge test data that quantify the capacity of a novel dynamically installed plate anchor in sand under drained monotonic and cyclic loading. The monotonic tests investigated the role of the eccentricity of the load attachment point from the plate, the mooring line load inclination at the seabed and the plate embedment depth, whereas the cyclic tests examined the capacity mobilisation due to both regular and irregular drained cyclic loading for a fixed embedment depth and seabed load inclination. The test data indicate that an optimal anchor design would employ a load attachment point that is eccentric from the plate by at least 0.6 times the plate height, and that the anchor provides higher capacity when the seabed load inclination is horizontal (catenary mooring) than when it is vertical (vertical taut mooring). The centrifuge data show that drained cyclic loading does not degrade anchor capacity, and may be beneficial provided the cyclic loading involves a history of lower level cyclic loading that densifies the sand.

Study on effective anchorage length of anchor cable based on Gauss's function

In the current relevant codes and technical standards, the design of anchor cables (bars) is based on the assumption that the shear stress is distributed uniformly along the anchor segment. However, according to this assumption, the super-deep pit need a large uplift bearing capacity, which will lead to the long anchor segment and has great hidden danger in the actual engineering design. Therefore, this paper, based on the previous derived shear stress function between τ and the anchor length, we get a research suitable model-Gauss curve distribution model through the analysis of saturated clay drawing data, and strata anchor shear stress distribution is more suitable for the Gauss function model in saturated clay; at the same time, through the FLAC numerical simulation of Jinan Government Affairs Center project, we obtained the optimal anchor effective anchor length is about 10~12m, the foundation pit anchor is optimized.

Design method of redundancy of brace-anchor sharing supporting based on cooperative deformation

Because of the complicated environment requirement, the support form of foundation pit is diversified, and the brace-anchor sharing support is widely used. However, the research on the force deformation characteristics and the related aspects of the cooperative response of the brace-anchor sharing support is insufficient. The application of redundancy theory in structural engineering has been more mature, but there is little theoretical research on redundancy theory in underground engineering. Based on the idea of collaborative deformation, the paper calculates the ratio of the redundancy degree of the cooperative deformation by using the local reinforcement design method and the structural component redundancy parameter calculation formula based on Frangopol. Combined with the engineering case, through the calculation of the ratio of cooperative deformation redundancy in the joint of brace-anchor sharing support. This paper explores the optimal anchor distribution form under the condition of cooperative deformation, and through the analysis and research of displacement field and stress field, the results of the collaborative deformation are validated by comparing the field monitoring data. It provides theoretical basis for the design of this kind of foundation pit in the future.

Anchor Spacing Design of Pre-Stressed Tunnel Concrete Lining with Un-Bonded Annular Anchors for Songhua River Water Supply Project

At present, annular anchor pre-stressed tunnel Concrete lining is the main design method of poor -quality surrounding rocks, thin covering and high internal water pressure tunnel. Based on the contact of tendons and concrete, the annular anchor lining can be classified into bonded and un-bonded. Cable spacing is one of the key parameters in the design of the un-bonded annular anchors pre-stressed concrete lining. The optimal anchor spacing can not only meet the demand of the project, but also save the cost of construction. In this paper, the anchor spacing is studied in the design of pre-stressed tunnel concrete lining with un-bonded annular anchors for Songhua River water supply project. The equivalent load method and solid modeling method are combined in Flac3d 3D modeling. Numerical simulation of pre-stressed effects for different anchor spacing in tension and operation of the concrete lining were analyzed. The optimal anchor cable spacing is received, which is a reference for the design and construction of similar projects in the future.