Loading Process Research Articles

Study on signal characteristics of burst tendency coal under different loading rates

In order to study the mechanics, acoustic emission (AE) and electromagnetic emission (EME) response law of bursting liability coal at different loading rates, uniaxial compression tests were carried out on coal mass from Konggu Coal Mine. The corresponding relations among mechanical properties, AE and EME signals in the process of coal failure under loading were analyzed, and the energy evolution law of coal failure with bursting liability under loading rate was discussed. The results show that within a certain range of loading rate, the higher the loading rate, the higher the compressive strength and peak load of bursting liability coal, and the shorter the time for coal to reach the peak load. Under different loading rates, the mechanics, AE and EME signals of coal samples can be well corresponded. When the loading rate is low, the number of blocks destroyed of coal sample is large and the block size is relatively small, and the blocks are mainly scattered around the test platform. When the loading rate is high, the number of damaged blocks is relatively small and the block size is relatively large, and the blocks are far away from the test bench. When loading at a low rate, the internal cracks in coal can be fully developed and connected, and the energy release rate is relatively uniform in the process of loading and failure of coal sample. In the case of high loading rate, the energy release rate of coal sample in the loading process is much smaller than that in the moment of failure. Combining the above test results with the actual situation of the working face, it can be concluded that the total energy stored in the coal of fast mining increases and the threshold of impact decreases compared with that of slow mining. Therefore, under the disturbance of external dynamic load, rapid mining is more likely to induce rock burst.

HCE2RNFC: An Efficient Methodology for Reusing the EHR in the Spanish National Hip Fracture Registry.

Hip fracture is a condition associated with ageing and frailty, with an associated prevalence of 7 per 10000 population in Spain. Evidence suggests that factors in the healthcare process can influence clinical outcomes, so the creation of a national registry is an opportunity to monitor and improve this process. In this regards, Electronic Health Record (EHR) can provide a large amount of data, that can be used to populate the Spanish National Hip Fracture Registry (RNFC, by its acronym in Spanish). However, this reuse of the EHR requires a prior effort in modelling and standardization to build the extraction, transformation, and loading (ETL) processes in a flexible, transparent, and scalable manner. In this work, a robust EHR reuse methodology is implemented to obtain EHR-derived data for the RNFC. The main result of this work was the design and implementation of an EHR data reuse methodology, which was able to load 1279 hip fracture cases and almost 68% of the required concepts from the RNFC.

Dynamic response and failure characteristics of the fluid-filled concave multicell structure under combined blast and fragments loading

The deformation and damage characteristics of the fluid-filled concave multicell structure under the charge explosion with preset fragments are investigated to assess its performance against combined blast and fragments loading. The failure characteristics of the structure, the propagation process of loads, and the dynamic response characteristics of the structure are analyzed using experimental research and SPH-ALE numerical simulation. The results indicate that the deformation of the structure, caused by the explosion of a charge with preset fragments, is 400% greater than the deformation caused by the explosion alone. The propagation of the load is influenced by the panels of the structure and the irregular regions where fluid is filled. The deformation and failure of the fluid-filled concave multicell structure occur in two stages. The failure mode of this structure can be seen as a combination of the failure modes of individual single-cell structures, based on the method of fluid filling. The strength distribution of the structure plays a crucial role in determining the failure of the fluid-filled concave multicell structure.

Cyclic tensile response and crack closure performance of novel superelastic Ni-Ti SMA cable grid-reinforced engineered cementitious composites

To further improve the tensile and self-healing properties of engineered cementitious composites (ECCs) for their special uses such as harsh environments, plastic hinge regions, and old members strengthening, an innovative high-performance superelastic Ni-Ti shape memory alloy (SMA) cable grid-reinforced ECC (SMACG-ECC) was first proposed and tested in this study. The effects of water-binder ratio, cable grid material, and reinforcement ratio on the cyclic tensile properties and crack closure performance of the proposed SMACG-ECC were systematically examined. Test results revealed that the tensile strength, initial crack strength, ultimate tensile strain, dense crack, crack closure, and self-healing properties of the traditional ECC were obviously improved by being reinforced with the SMACG. Compared with the ordinary steel cable grid-reinforced ECC (SCG-ECC), the proposed SMACG-ECC exhibited approximately 50 % lower first crack strength, similar tensile strength and deformation ductility, but a 53.7 %-75.1 % greater energy dissipation, 75.8 %-80.2 % lower residual strain, and 80.4 %-83.4 % smaller maximum residual crack width. The tensile properties, cracking performance, and self-healing ability improved with the incorporation of SMACG as well as the increase in reinforcement ratio. Notably, most specimens showed satisfactory composite operation with no cable ends slipping during the entire cyclic loading process, with a maximum tensile strain amplitude of 8 %.

Controlled Release of Curcumin and Hypocrellin A from Electrospun Poly(l-Lactic Acid)/Silk Fibroin Nanofibers for Enhanced Cancer Cell Inhibition.

Nanofibers have emerged as a highly effective method for drug delivery, attributed to their remarkable porosity and ability to regulate drug release rates while minimizing toxicity and side effects. In this study, we successfully loaded the natural anticancer drugs curcumin (CUR) and hypocrellin A (HA) into pure poly(l-lactic acid) (PLLA) and PLLA-silk protein (PS) composite nanofibers through electrospinning technology. This result was confirmed through comprehensive analysis involving SEM, FTIR, XRD, DSC, TG, zeta potential, and pH stability analysis. The encapsulation efficiency of all samples exceeded 85%, demonstrating the effectiveness of the loading process. Additionally, the drug release doses were significantly higher in the composites compared to pure PLLA, owing to the enhanced crystallinity and stability of the silk proteins. Importantly, the composite nanofibers exhibited excellent pH stability in physiological and acidic environments. Furthermore, the drug-loaded composite nanofibers displayed strong inhibitory effects on cancer cells, with approximately 28% (HA) and 37% (CUR) inhibition of cell growth and differentiation within 72 h, while showing minimal impact on normal cells. This research highlights the potential for controlling drug release through the manipulation of fiber diameter and crystallinity, paving the way for wider applications of electrospun green nanomaterials in the field of medicine.

The interplay of perceptual processing demands and practice in modulating voluntary and involuntary motor responses.

Understanding how sensory processing demands affect the ability to ignore task-irrelevant, loud auditory stimuli (LAS) during a task is key to performance in dynamic environments. For example, tennis players must ignore crowd noise to perform optimally. We investigated how practice affects this ability by examining the effects of delivering LASs during preparatory phase of an anticipatory timing (AT) task on the voluntary and reflexive responses in two conditions: lower and higher visual processing loads. Twenty-four participants (mean age = 23.1, 11 females) completed the experiment. The AT task involved synchronizing a finger abduction response with the last visual stimulus item in a sequence of four Gabor grating patches briefly flashed on screen. The lower demand condition involved only this task, and the higher demand condition required processing the orientations of the patches to report changes in the final stimulus item. Our results showed that higher visual processing demands affected the release of voluntary actions, particularly in the first block of trials. When the perceptual load was lower, responses were released earlier by the LAS compared to the high-load condition. Practice reduced these effects largely, but high perceptual load still led to earlier action release in the second block. In contrast, practice led to more apparent facilitation of eyeblink latency in the second block. These findings indicate that a simple perceptual load manipulation can impact the execution of voluntary motor actions, particularly for inexperienced participants. They also suggest distinct movement preparation influences on voluntary and involuntary actions triggered by acoustic stimuli.

Analisis Kendala Pelayanan Jasa Bongkar Muat Peti Kemas Terhadap Kelancaran Operasional pada Perusahaan Ekspedisi Muatan Kapal Laut

Container services are services related to the use of containers or containers in the process of shipping goods. The container itself is a special container used to pack and transport goods efficiently, especially in trade. In the process of putting goods or stuffing goods that are packaged in the form of pallets, metal boxes and bulk. The process to enter a 20-foot or 40-foot container is determined by the number of buyer requests. The author chose qualitative descriptive research because this research is in accordance with the nature of the author's research which is descriptive and uses interview techniques, documentation, and others. In addition, this research is also in accordance with the practical research objectives. Mistakes in container stock management can have a devastating impact on the company, such as damage to goods, additional costs, and a tarnished reputation. To improve container loading and unloading services, companies need to improve communication, employee training, truck checks, forklift maintenance, and collaboration with service users. The process of shipping goods through the port involves various stages and parties such as consignees, suppliers, shippers, and field executives. The results of the study can be found that the process of container loading and unloading services in expedition companies experiences various obstacles, such as late truck drivers, delays in sending documents, shortage of containers, damage to container moving equipment at the depot, delays in the start of working hours, and too many containers that do not comply with the specifications by the exporter.

How to customize common data models for rare diseases: an OMOP-based implementation and lessons learned

BackgroundGiven the geographical sparsity of Rare Diseases (RDs), assembling a cohort is often a challenging task. Common data models (CDM) can harmonize disparate sources of data that can be the basis of decision support systems and artificial intelligence-based studies, leading to new insights in the field. This work is sought to support the design of large-scale multi-center studies for rare diseases.MethodsIn an interdisciplinary group, we derived a list of elements of RDs in three medical domains (endocrinology, gastroenterology, and pneumonology) according to specialist knowledge and clinical guidelines in an iterative process. We then defined a RDs data structure that matched all our data elements and built Extract, Transform, Load (ETL) processes to transfer the structure to a joint CDM. To ensure interoperability of our developed CDM and its subsequent usage for further RDs domains, we ultimately mapped it to Observational Medical Outcomes Partnership (OMOP) CDM. We then included a fourth domain, hematology, as a proof-of-concept and mapped an acute myeloid leukemia (AML) dataset to the developed CDM.ResultsWe have developed an OMOP-based rare diseases common data model (RD-CDM) using data elements from the three domains (endocrinology, gastroenterology, and pneumonology) and tested the CDM using data from the hematology domain. The total study cohort included 61,697 patients. After aligning our modules with those of Medical Informatics Initiative (MII) Core Dataset (CDS) modules, we leveraged its ETL process. This facilitated the seamless transfer of demographic information, diagnoses, procedures, laboratory results, and medication modules from our RD-CDM to the OMOP. For the phenotypes and genotypes, we developed a second ETL process. We finally derived lessons learned for customizing our RD-CDM for different RDs.DiscussionThis work can serve as a blueprint for other domains as its modularized structure could be extended towards novel data types. An interdisciplinary group of stakeholders that are actively supporting the project's progress is necessary to reach a comprehensive CDM.ConclusionThe customized data structure related to our RD-CDM can be used to perform multi-center studies to test data-driven hypotheses on a larger scale and take advantage of the analytical tools offered by the OHDSI community.

Macrocycle-Based Supramolecular Drug Delivery Systems: A Concise Review.

Efficient delivery of therapeutic agents to the lesion site or specific cells is an important way to achieve "toxicity reduction and efficacy enhancement". Macrocycles have always provided many novel ideas for drug or gene loading and delivery processes. Specifically, macrocycles represented by crown ethers, cyclodextrins, cucurbit[n]urils, calix[n]arenes, and pillar[n]arenes have unique properties, which are different cavity structures, good biocompatibility, and good stability. Benefited from these diverse properties, a variety of supramolecular drug delivery systems can be designed and constructed to effectively improve the physical and chemical properties of guest molecules as needed. This review provides an outlook on the current application status and main limitations of macrocycles in supramolecular drug delivery systems.

Linear fractal evolution characteristics of rock crack distributions during loading process

To investigate the fractal characteristics of rock crack distributions during the loading process, discrete element method was used to make rock samples with joints and record the crack propagation. The Box-counting method was used to quantitatively analyze the fractal dimension of the crack distribution at each moment, and the relationship between the crack fractal dimension and strain ratio was established based on fractal theory. The results indicated that the relationship between the fractal dimension of the crack distribution and strain ratio showed a strong linear characteristic. By transforming this linear relationship into a linear function, the slope of the function was found to be linked to the failure patterns of the sample, and a refinement coefficient (damage-fracture reduction factor) was identified from the slope as an effective basis for determining the degree of sample damage and fracture. The damage-fracture reduction factor can be categorized: 0.25–0.5 (spilt and fracture), 0.5–0.9 (synergy between fracture and damage), 0.9–1 (microcrack asymptotic damage). Owing to the linear fractal characteristics, an expression for the damage variables influenced by failure patterns can be established from the geometric aspect. In addition, the linear fractal characteristics of the cracks were verified in other acoustic emission and crack extension experiments.

Mechano-Responsive Polymers and Nanocomposites: Recent Advances for Self-Adaptive Structural Applications.

Polymer nanocomposites exhibiting remarkable mechanical properties are a focus of research for decades in structural applications. However, their practical application faces challenges due to poor interfacial load transfer, nanofiller dispersion, and processing limitations. These issues are critical in achieving stiff, strong, lightweight, and structurally integrated materials. Additionally, they often suffer from predetermined properties, which may not be effective under specific loading conditions. Addressing these challenges, the development of design strategies for mechano-responsive materials has advanced, enabling self-adaptive properties that respond to various mechanical stimuli. Drawing inspiration from natural systems, these approaches have been implemented in synthetic material systems, leveraging the design flexibility of nanocomposites as needed. Key focus areas include exploring mechanoradical reactions for dynamic mechano-responsiveness, as well as utilizing biomimetic mineralization and mechanical training for self-strengthening. This work also examines multistability, enabling on-demand deformation of materials and structures. Recent advancements in viscoelastic damping and nonreciprocal materials are discussed, highlighting their potential for directional energy absorption, transmission, and vibration control. Despite the need for significant improvements for real-world applications, mechano-responsive polymers and nanocomposites are expected to offer enormous opportunities not only in structural applications but also in other fields such as biomedical engineering, energy harvesting, and soft robotics.

Research on the Method for Recognizing Bulk Grain-Loading Status Based on LiDAR.

Grain is a common bulk cargo. To ensure optimal utilization of transportation space and prevent overflow accidents, it is necessary to observe the grain's shape and determine the loading status during the loading process. Traditional methods often rely on manual judgment, which results in high labor intensity, poor safety, and low loading efficiency. Therefore, this paper proposes a method for recognizing the bulk grain-loading status based on Light Detection and Ranging (LiDAR). This method uses LiDAR to obtain point cloud data and constructs a deep learning network to perform target recognition and component segmentation on loading vehicles, extract vehicle positions and grain shapes, and recognize and make known the bulk grain-loading status. Based on the measured point cloud data of bulk grain loading, in the point cloud-classification task, the overall accuracy is 97.9% and the mean accuracy is 98.1%. In the vehicle component-segmentation task, the overall accuracy is 99.1% and the Mean Intersection over Union is 96.6%. The results indicate that the method has reliable performance in the research tasks of extracting vehicle positions, detecting grain shapes, and recognizing loading status.

Effect of Bedding Angle on Energy and Failure Characteristics of Soft–Hard Interbedded Rock-like Specimen under Uniaxial Compression

To investigate how bedding planes affect the energy evolution and failure characteristics of transversely isotropic rock, uniaxial compression tests were conducted on soft–hard interbedded rock-like specimens with varying bedding angles (α) using the RMT-150B rock mechanics loading system. The test results indicate that throughout the loading process, the energy evolution shows obvious stage characteristics, and the change of α mainly affects the accelerating energy dissipation stage and the full energy release stage. With the increase of α, the ability of rock to resist deformation under the action of energy shows the characteristics of “strong–weak–strong”. The energy dissipation process is accelerated by medium angle bedding planes (α = 45°~60°). The precursor points of the ratios of dissipation energy to total energy (RDT) and elastic energy to dissipation energy (RED) can be used to effectively predict early failure. With the gradual increase of α, the difficulty of crack development is gradually reduced. The changes of energy storage limitation and release rate of releasable elastic energy are the immanent cause of different macroscopic failure modes of specimens with varying α.

Modifikasi Produksi dan Biaya Bahan Bakar Minyak pada Kapal Ciremai

Some of the main research problems are the lack of fuel efficiency use, difficulties in loading and unloading process, the refueling process tardiness and the ships route’s delay of the determined and planned routes that could affect the Ciremai Ship’s On Time Performance (OTP). The research aims to determine and analyze the effect of production and fuel oil cost modifications based on the income of Ciremai Ship and its implications for its financial performance after “Three in One” modification. This research used Descriptive statistical analysis method and hypothesis testing using SmartPLS-3. The research sample was taken from the entire routes of Ciremai Ship over the last four years of 48 months. The secondary research data was taken from the financial reports related to production modifications, fuel oil costs, the income and financial performance of the ship. Research findings show that the production modifications have a direct influence on financial performance while fuel costs and income do not have a direct influence on it. The production modifications do not have a direct effect on income instead fuel costs have a direct effect on income and production modifications do not have an indirect effect on financial performance through income.

Loading co-amorphous on Metal-Organic Frameworks for gelation elimination and anti-cancer drug delivery enhancement

Troublesome gelation occurring during the dissolution of special co-amorphous (COAM) systems poses a limitation on their further applications. Metal-Organic Frameworks (MOFs) are promising porous materials for nano-scale drug delivery due to their high loading capacity and ability to control drug release. Examples of MOFs as drug carriers with the confinement effect for COAM drugs have never been reported. In this study, to eliminate the gelation of the COAM of an anti-cancer drug gefitinib (GTB) and co-former saccharin (SAC) for enhancing their anti-cancer drug delivery, a Zr-based MOF, nanoUiO-67, was selected as drug carrier. The loading process of GTB-SAC COAM on nanoUiO-67 was revealed via a real-time spinning disk confocal fluorescence microscope. The maintenance of molecular interactions between GTB and SAC in GTB-SAC COAM after loaded on nanoUiO-67 was proven experimentally and computationally, along with the host (nanoUiO-67)-guest (drug) interactions. The combined advantages of porous materials nanoMOFs and GTB-SAC COAM were fully demonstrated in terms of excellent physical stability, desirable drug release, good bio-compatibility and higher cytotoxicity towards HeLa cells. It is expected that this novel strategy could have potential application in gelation elimination and developing multi-component drug-loaded MOFs.

'Where have my patients gone?': A simulation study on real-world data processing in Clinical Data Warehouses

ObjectiveTo access Electronic Health Record (EHR) data, hospitals have implemented Clinical Data Warehouses (CDWs) using Extract Transform and Load (ETL) processes. While ETL performances are typically evaluated individually, our study examines the cumulative impact of ETLs on data availability. MethodsUsing a real multi-hospital CDW as a case study, we modeled EHR data processing from the software sources to the CDW's data store. We simulated a scenario where researchers aimed to reconstruct breast cancer care trajectories using EHR data. We calculated the size and characteristics of the data store population, and compared them to the original population. ResultsEHR data are recorded in various software depending on data category, hospital, and year, each requiring specific series of ETLs for integration in the CDW. Despite acceptable transfer rates for each ETL (range 73 %-100 %), cumulative losses led to study populations in the data store being up to 90 % smaller than anticipated when researchers required data exhaustivity for patients. Population size decreased steeply with the more data categories required. No difference was found in population characteristics between the data store and the original cohorts. Discussion & ConclusionResearchers should scrutinize data availability in CDWs as missing data could result from outsourced care, incomplete input, or underperforming ETLs. Integrating more data sources in CDWs increases the number of data routes, necessitating time for ETL implementation and maintenance, and increases data loss risks. Though commonly perceived as a “black box”, data transformation can significantly influence the reliability of populations studied in CDWs. Public interest SummaryTo access data generated during care, researchers build Clinical Data Warehouses (CDWs). CDWs are infrastructures composed of a series of processing steps to extract the data from the data source, transform it according to the needs and load it into a data store. Usually, the performances of these processing steps are evaluated one a time. However, each data point goes through a series of processing steps before being made available for research. In this study, we aim to evaluate the impact of the entire data processing pipeline on the availability of data points in a CDW by simulating a study on breast cancer and evaluating the impact on the size and the characteristics of the final cohort. The cumulative losses of the processing steps resulted in a population 90 % smaller than anticipated. The characteristics of the final population showed no difference to those of the original cohort.

Brain correlates of attentional load processing reflect degree of bilingual engagement: Evidence from EEG

The present study uses electroencephalography (EEG) with an N-back task (0-, 1-, and 2-back) to investigate if and how individual bilingual experiences modulate brain activity and cognitive processes. The N-back is an especially appropriate task given recent proposals situating bilingual effects on neurocognition within the broader attentional control system (Bialystok and Craik, 2022). Beyond its working memory component, the N-Back task builds in complexity incrementally, progressively taxing the attentional system. EEG, behavioral and language/social background data were collected from 60 bilinguals. Two cognitive loads were calculated: low (1-back minus 0-back) and high (2-back minus 0-back). Behavioral performance and brain recruitment were modeled as a function of individual differences in bilingual engagement. We predicted task performance as modulated by bilingual engagement would reflect cognitive demands of increased complexity: slower reaction times and lower accuracy, and increase in theta, decrease in alpha and modulated N2/P3 amplitudes. The data show no modulation of the expected behavioral effects by degree of bilingual engagement. However, individual differences analyses reveal significant correlations between non-societal language use in Social contexts and alpha in the low cognitive load condition and age of acquisition of the L2/2L1 with theta in the high cognitive load. These findings lend some initial support to Bialystok and Craik (2022), showing how certain adaptations at the brain level take place in order to deal with the cognitive demands associated with variations in bilingual language experience and increases in attentional load. Furthermore, the present data highlight how these effects can play out differentially depending on cognitive testing/modalities – that is, effects were found at the TFR level but not behaviorally or in the ERPs, showing how the choice of analysis can be deterministic when investigating bilingual effects.

Supply Chain System Optimization Model for Logistics Enterprises in the Internet of Things Era Based on Improved ECC Algorithm

In this article, a new method to optimize the supply chain system (SCS) of logistics companies in the era of Internet of Things (IoT) using an improved elliptic curve cryptography (ECC) algorithm was put forward.The focus of this research was to address the challenges faced by logistics organizations in adapting to the complexity of modern supply chains and meeting the growing demands of customers. The research aimed to improve the efficiency, security and reliability of supply chain management systems by utilizing advances in ECC algorithms.By conducting comprehensive performance tests of the proposed system, including interface testing, joggle testing, and system response time analysis, the study demonstrated the superiority of the system over traditional systems. The research findings indicated that the system based on the improved ECC algorithm outperformed traditional systems in terms of interface effectiveness, usability, and system response time. The improved ECC algorithm enhanced the security of the encryption process, making it more resistant to unauthorized access, and improved the system’s overall data processing load capacity. Additionally, the system demonstrated superior performance in managing logistics data and information, facilitating better decision-making and efficiency in logistics operations. Overall, this research contributes to the advancement of supply chain management in the IoT era by providing a practical and efficient solution for logistics enterprises to optimize their supply chain systems. The innovative application of the improved ECC algorithm offers a secure, reliable, and efficient approach to managing logistics operations, addressing the challenges posed by the complexities of modern supply chains.

Reducing overnight charges in the loading process of finished goods using FMEA method at PT. XYZ

As a part of the supply chain, the logistics department plays a crucial role in the operational activities of a company. Like other departments, the logistics department also incurs costs that do not add value, such as overnight charges. Failure in the loading of finished goods process can result in a dwell time exceeding 18 hours per vehicle, leading to overnight charges. This occurrence can be prevented by identifying risks and failure modes using Failure Mode and Effect Analysis (FMEA). The FMEA methodology is widely utilized across various industries, including manufacturing, for product development. Additionally, FMEA is frequently employed in failure analysis in service industries, food services, construction, mining, agriculture, and healthcare. The research was conducted to identify failure modes and potential causes in the loading of finished goods process. In PT. XYZ, there are five finished goods storage areas. From the process of weigh-in time, loading finish goods, and weigh-out time, 25 activities were analyzed, and seven activities with the highest Risk Priority Number (RPN) were selected for solutions. The activity with the highest RPN, scoring 512, was the queuing of trucks exceeding loading capacity. The why-why analysis technique was employed to assist in finding solutions. From the seven activities with the highest RPN, 9 solution plans were derived. The recommendation to reduce queue trucks is to organize and monitor the vehicles dispatched by the Freight Forwarder. As a result, the dwell time per vehicle decreased from 9.23 hours to 6.36 hours, and the overnight charges reduced from 148,145 USD to 12,345 USD

The progressive failure features of shield tunnel lining with large section

Investigating the failure process of segmental lining is of great significance to the design and maintenance of shield tunnel. Indoor scaled model tests are carried out to study the inner force, structural displacement, acoustic emission signals and damage pattern of lining. Meanwhile, a new numerical approach is put forward based on particle element method to study the influence of geo-stress field and the position of void or key block to the failure features of lining. The results showed that the failure of lining is progressive and can be divided into four stages, that is, the initial elastic stage, meso-damage stage, macroscopic failure stage and overall instability stage. For the key block is located at the crown, there are two concentrated intervals for the generation of micro-cracks. For the key block is located on the spandrel, micro-cracks are uniformly produced throughout the loading process after the initial elastic stage. For the key block is located on the haunch, micro-cracks distributed in a large concentrated range. The influence of the position of void on the damage of lining can be divided into three kinds, namely, no effect; affecting the emerging order of cracks while not final fracture pattern; affecting the emerging order of cracks and the final fracture pattern.