Penetration Method Research Articles

Estimation of Nitrogen Oxides (NOx) Removal Efficiency for TiO2 Concrete

Nitrogen oxide (NOx) is a significant precursor of particulate matter (PM), particularly in high-traffic areas. Accordingly, this study aimed to reduce the presence of nitrogen oxide (NOx) along roadsides. Titanium dioxide (TiO2) is used as a photocatalyst to remove NOx through a chemical reaction. Typically, concrete and TiO2 are mixed to create TiO2 concrete. However, air pollutants or UV rays cannot be allowed to come into contact with a significant amount of TiO2. Thus, the TiO2 surface penetration method was used to fix TiO2 to the surface of the concrete. In this method, surface penetrants and TiO2 are combined and sprayed onto the concrete surface, enabling the possibility of NOx reduction using relatively less TiO2. When the fixation method is applied to vertical concrete structures, however, a peeling issue arises. To address this, a pressurized TiO2 fixation method was applied to vertical concrete structures. This method uses external force to penetrate and fix TiO2 to a specific depth. In the instance of the pressurized TiO2 fixation method, which was tried for the first time, penetration depth was used to ensure long-term durability as well as NOx removal efficiency. To investigate TiO2 distribution characteristics, the penetration depth and mass ratio of TiO2 particles in TiO2 concrete were measured using a scanning electron microscope (SEM/EDX). In addition, NOx removal efficiencies were evaluated using the NOx analyzing system (ISO 22197-1 standard). The experimental results showed that NOx removal efficiency increased with an increasing TiO2 mass ratio. When the TiO2 fixation method was used, the NOX removal efficiency was 32% when the TiO2 mass ratio at the surface was 50%, and the efficiency was 61% when the TiO2 mass ratio was 70%. This is attributed to the increase in NOx removal efficiency as TiO2 content at the concrete surface increases. This study analyzed and forecasted the NOx removal efficiency of TiO2 concrete based on the mass ratio of TiO2 on the surface. As the TiO2 mass ratio increased, the NOx removal efficiency improved, and it was determined that the surface TiO2 mass ratio significantly influences the NOx removal efficiency. Consequently, this study developed an equation to estimate NOx removal efficiency, making it possible to determine a suitable maintenance interval for TiO2 concrete.

Rapid positioning test method for cylindrical structure penetration based on machine learning

Focusing on the requirements of rapid damage location test for multi-layer steel plates penetration of cylindrical structure in the complex and harsh environment, this paper studies the propagation characteristics of high-speed impact stress waves in steel plates. Also, the measurement effects of impact stress in the near zone of penetration hole are compared with different sensors, so as to select appropriate PZT sensors to measure the velocity of impact stress wave in the actual steel plates. Then the array layout scheme is designed, and the corresponding damage location algorithm is determined. Finally, the deep learning algorithm is used to improve the accuracy and efficiency of damage location.

Effect of cervical margin relocation on marginal adaptation and microleakage of indirect ceramic restorations.

This study evaluated the effect of cervical margin relocation (CMR) with two different materials and contamination with hemostatic agents on the margin adaptation and microleakage of ceramic restorations. Mesial-occlusal-distal cavities were prepared in 60 human first molars and distributed to 3 groups (n=20) according to the margin relocation procedure. The groups were: group F; flowable composite applied in two 2mm increments, group B; bulk-fill flowable composite applied as a bulk increment of 4mm thickness and group C (control); no CMR was done. Each group was subdivided into two subgroups (subgroup N; no hemostatic agent applied and subgroup H; hemostatic agent was applied). In all groups, ceramic inlays were prepared and cemented. The samples were subjected to thermocycling (10,000 cycles). The adaptation of the cervical margin was evaluated with scanning electron microscopy (200×). Samples were then assessed for microleakage analysis with the dye penetration method. Marginal adaptation data were normally distributed and analyzed using two-way ANOVA followed by Tukey's post hoc test. Ordinal microleakage score data were analyzed using cumulative link models followed by the analysis of deviance using Wald chi-square tests. Both CMR and contamination with a hemostatic agent had significant effects on the margin adaptation of the cervical margin. Group C showed the highest adaptation with no significant difference from group F. The lowest adaptation was revealed in group B with a significant difference from group C. Subgroup N (in all groups) showed a statistically higher adaptation than subgroup H. Regarding microleakage assessment, CMR had no significant effect but hemostatic agent application showed a significantly higher microleakage score for all groups. Both the CMR procedure and contamination with AlCl3 hemostatic agent had a negative effect on marginal adaptation. For microleakage assessment, only contamination with hemostatic agent negatively affected the microleakage with no effect on the margin relocation procedure.

Newer Possibilities for Proximal Box Elevation – Tooth Substrate and Comparison with Conventional Materials: An Ex-vivo Study

Background: Adhesive bonding in deep sub-gingival areas is a challenge due moist environment leading to poor marginal seal and microleakage in deep class II cavities. The deep margin elevation technique is advocated in such areas.
 Aim: The aim of this study is to evaluate enamel, a natural substrate as an alternative material for deep margin elevation, and compare it with the resin-modified glass ionomer and composite material by evaluating microleakage at the tooth-restoration interface in Class II cavities.
 Materials and Methods: For this study 21 patients having at least one tooth indicated for extraction and 7 patients having at least two teeth indicated for extraction were included.Class II cavities were prepared on the 28 teeth with proximal margins 1mm below the CEJ and were divided into 4 groups(n=7) Group 1: flowable composite was used for deep margin elevation(DME) up till 2mm above CEJ, Group 2: RMGIC was used for DMEup till 2 mm above CEJ, Group 3: enamel slab luted with RMGIC (for DME)up till 2mm above CEJ,enamel slab obtained from other seven teeth of same patient also indicated for extraction, Group 4(control): no intermediate material was used for margin elevation. Then the remaining part of the cavities were restored using the FILTEK P60. The prepared teeth were extracted after one week. The class II cavities were evaluated for microleakage using dye penetration method.
 Results: RMGIC and enamel slab showed significantly less microleakage as compared to flowable composite and the control group. However there was insignificant difference between RMGIC and Enamel slab group. The control group exhibited highest microleakage as compared to all the other groups.
 Conclusion: RMGIC and enamel slab exhibit least microleakage when used as materials for deep-margin elevation.

Study on penetration resistance for thin-walled bucket foundation in muddy clay

In view of the problem that the resistance reduction effect of ring stiffeners is not considered in the existing calculation methods of penetration resistance, based on the field penetration date of thin-walled bucket foundation with ring stiffeners and combined with the field installation situation, the resistance reduction effect of the angle iron ring stiffeners on the skin friction resistance was explored, the calculation method of the penetration resistance considering the resistance reduction coefficient β was proposed. The results show that because the resistance reduction effect of ring stiffeners is not considered, the calculation results of the standard and theoretical equation method are larger than the measured resistance. The end resistance increased by ring stiffeners is about 55%–65% of the end resistance calculated by the standard and theoretical equation method, the end resistance increased by ring stiffeners should be considered in actual project. It is proposed that the calculation method considering the resistance reduction coefficient β can accurately predict the penetration resistance and the required differential pressure of bucket foundation with ring stiffeners, the recommended resistance reduction coefficient is 0.52 for the static penetration method, 0.33 for the undrained shear strength method, and 0.31 for the c and φ parameter method.

Assessment of microleakage and interfacial adaptation following simultaneous activation technique in primary molars

Simultaneous Activation Technique is a newer method of co-curing resin modified glass ionomer (RMGI) and self-etch adhesive. Assessment of microleakage and interfacial adaptation following simultaneous activation technique in primary molars. Standardized Class I cavities were prepared in 66 non-carious primary molars and randomly allocated to Group I – Simultaneous activation of RMGI and self-etch adhesive (SAT); Group II – SAT with enamel etching (SAT + EE); Group III – Conventional Sandwich Technique (ST) and restored with bulk fill composite. Time taken was calculated using stopwatch. Microleakage was assessed using dye penetration method under stereomicroscope. Seven samples per group were sent for Scanning Electron Microscopy (SEM) analysis. One-Way Analysis of Variance and Post- Hoc Tukey's test were applied at P < 0.05. Mean microleakage of group I, II and III were 1.23, 1.41 and 1.59 respectively. Time taken was least for SAT followed by SAT + EE and ST group. Statistically significant difference was seen between SAT and ST group (p < 0.0001) and SAT + EE and ST group (p < 0.0001). SEM analysis showed better mean interfacial adaptation in SAT + EE (1.00) followed by ST (2.14) and SAT (3.57) group. Difference between SAT + EE and SAT group was significant (p = 0.005). Simultaneous activation technique with selective enamel etching resulted in less microleakage and better interfacial adaptation.

Theoretical and Experimental Research on the Evolution of the Friction Coefficient in Different Lubrication Conditions in the Case of Friction Couples with Sliding Motion

Abstract In recent decades, the interest of researchers and engineers in obtaining competitive materials is increasing. The effects of friction on materials are quite difficult to explain due to the micro and macroscopic interactions of the surfaces of the friction couple, which slide over each other. The friction and wear behavior of sliding surfaces can be considered important design criteria. The fact that for a kinematic coupling with sliding motion, a material with a higher hardness is used in most cases in combination with a material with a lower hardness, there is the possibility of abrasion wear and local plastic deformations. The paper proposes in analytical model for calculating the coefficient of friction when a rigid conical penetrator passes over a flat surface with a lower hardness and establishing the response mode of the material of the flat surface. The penetration method corresponds to the deformation produced by asperities in practice. The proposed theoretical model will be experimentally validated on a tribological stand made in this sense. Comparing the experimental results with the theoretical ones confirms the veracity of the model and also corresponds to many of the experimental results obtained in specialized works.

Research on damage effect of penetration and explosion integration based on volume filling method

It is difficult to distinguish the damage effects of penetration and explosion loads in the test of projectile penetration and explosion integration. At present, there is no mature method to simulate the whole process of projectile penetration and dynamic explosion integration. To solve this problem, a numerical simulation method of projectile penetration and explosion integration based on the volume filling method is proposed, the explosive material is generated by volume filling in the background grid (ALE), and given the same initial velocity as the cartridge case. The fluid-structure coupling algorithm is set to restrict the cooperative deformation and movement of the cartridge case and the explosive, the static or dynamic explosion occurred after the cartridge case and the explosive penetrate the target medium synchronously. The empirical formula is used to verify the model of the inert projectile penetration process, and the numerical simulation of the whole process of penetration and dynamic explosion integration and penetration and static explosion integration is completed. The change rule of the medium internal pressure field, surface crater, and crater depth are given, and the damage effects of penetration and explosion loads in the process of penetration and explosion integration are quantitatively analyzed. The results show that: when the penetration and dynamic explosion integration, the non-dissipated penetration wave field in the target medium will be superimposed with the explosion shock wave field, and the pressure peak is higher than that of the single explosion wave field of charge static explosion after penetration, but it is not obvious; When the penetration and dynamic explosion integration, the dynamic explosive effect of the explosive makes the explosion shock wave field in the medium present an irregular spherical distribution, which has an influence that can not be ignored. When the target velocity is fixed, the later the initiation time is, the smaller the surface crater is and the greater the crater depth is; In the case of fixed initiation depth, the greater the target velocity, the smaller the surface crater, and the greater the crater depth.

A Penetration Method for UAV Based on Distributed Reinforcement Learning and Demonstrations

The penetration of unmanned aerial vehicles (UAVs) is an essential and important link in modern warfare. Enhancing UAV’s ability of autonomous penetration through machine learning has become a research hotspot. However, the current generation of autonomous penetration strategies for UAVs faces the problem of excessive sample demand. To reduce the sample demand, this paper proposes a combination policy learning (CPL) algorithm that combines distributed reinforcement learning and demonstrations. Innovatively, the action of the CPL algorithm is jointly determined by the initial policy obtained from demonstrations and the target policy in the asynchronous advantage actor-critic network, thus retaining the guiding role of demonstrations in the initial training. In a complex and unknown dynamic environment, 1000 training experiments and 500 test experiments were conducted for the CPL algorithm and related baseline algorithms. The results show that the CPL algorithm has the smallest sample demand, the highest convergence efficiency, and the highest success rate of penetration among all the algorithms, and has strong robustness in dynamic environments.

A comparative evaluation of micro shear bond strength and microleakage between the resin-modified glass ionomer cement and residual dentin following excavation of carious dentin using Carie CareTMand conventional caries removal in primary teeth: an in vitro study.

52 primary teeth with dentinal caries were randomly grouped into group I, where caries removal was done using the conventional method, and group II which used Carie Care TM. All the teeth were restored using RMGIC. Micro shear bond strength between the residual dentin and the cement was tested using universal testing machine and the dye penetration method was used for microleakage testing. Independent t-test was performed for intergroup comparison. Pearson chi-square test was carried out to evaluate the microleakage patterns in the enamel and dentin. The mean micro-shear bond strength of group I was 6.03±1.6 and that of group II was 8.54±2.92; this difference was statistically significant with a p-value of 0.012. Microleakage was higher in the test group (1.38±0.51) than the control group (0.77±0.6) and was significant with a p -value of .036. Papain-based chemomechanical agent Carie Care TMcan be used as an alternative method to conventional caries removal. However, further studies need to explore methods to improve the marginal sealing capacity of RMGIC to the residual dentin after chemomechanical caries removal.

The synthesis, characterization, and mechanism of a dense plate-like C-S-H based on cation exchange membrane-templating

An ordered structure and high mechanical property of calcium silicate hydrate (C-S-H) gel has been always pursued in the field of cementitious materials. In this paper, compacted and layer-by-layer stacking C-S-H plates were fabricated based on Layer-by-Layer (LBL) method and H-cell penetration (HCP) method through cation exchange membrane templating. This new way changed the randomly packing structure of traditional C-S-H, and synthesized a high-orderly C-S-H platelets with denser structure. Based on molecular dynamics simulations, it can be attributed to the strong adsorption and nucleation sites contributed by sulfonic acid groups on the cation exchange membrane. Besides, AFM indentation experiments indicate this C-S-H owns significantly higher elastic modulus than traditional C-S-H, while the mechanical properties can be further increased by the addition of PVA and the regulation of reaction time. This new type C-S-H may pave the way to the preparation of high-performance concrete in the future.

A Simple and Practical Tool for Indirect Determination of the Unconfined Compressive Strength of Most Common Construction Materials

Determination of the unconfined compressive strength (UCS) of construction materials in the laboratory is tedious and time-consuming. There have been many attempts to indirectly predict UCS using simpler tools and techniques. One of them is the nail gun. The scope of this investigation is to design a nailer which can be applied all construction materials whose UCS range from 1-100 MPa. In the research, rocks, bricks, and concretes prepared in different cement/sand ratios with different strength ranges were used as materials. The unconfined compressive strength of the materials used in the experiments was first determined by conventional compression tests. The nail penetration depths were determined by conducting experiments on the same materials using a nailer with two different energy levels. An empirical relationship was developed by using nail penetration depths, driving energies, and nail diameters as the independent variables and the UCS determined by the conventional method as the dependent variable. According to the empirical relationship determined by multiple regression analysis, the UCS of building materials can be estimated with significance level of 99% by the nail penetration method. The research also revealed that the UCS of rocks might have a coefficient of variation as high as 30%.

Cyclic performance of severely earthquake-damaged RC bridge columns repaired using grouted UHPC jacket

The bridges constructed in high seismic zones may suffer one or more earthquake shocks of certain scales during their service life. Some of them could be severely damaged during a catastrophic earthquake event. How to quickly and economically restore bridge service functions and traffic lifelines has always been the concern of bridge owners and engineers. In this study, a method for repairing seismically damaged reinforcement concrete (RC) bridge columns using ultrahigh performance concrete (UHPC) materials was developed. Seven down-scale RC bridge column specimens with three different reinforcement ratios and two different heights were designed according to the seismic design code for RC bridges. For three of the specimens, the reinforcement around the plastic hinge area were artificially corroded through chloride ion penetration method to simulate the strength degradation effect of reinforcement erosion that could occur in many aging bridge columns. All seven specimens were tested by applying cyclic loads until their plastic hinge became severely damaged, which were then repaired following the proposed procedure and with different jacket thicknesses. The cyclic tests were re-conducted for these repaired specimens. The testing results were analyzed by comparing to those from the test for the non-seismic-damaging specimens one by one with respect to their seismic performance in order to validate the seismic rehabilitation effect using UHPC materials. Additionally, an ABAQUS software based finite element model was developed for numerically simulating the hysteretic behaviors of the columns repaired using UHPC jacket. The resulting hysteretic curves for the repaired columns with different reinforcement ratios and heights well matched those from the corresponding cyclic tests. This model can be further used for seismic performance prediction and UHPC jacket design for the repaired bridge columns that have different dimensions and reinforcement configurations. All of these experimental and analytical results show that the seismic performance of the repaired bridge columns can be effectively restored in a relatively fast and low-cost manner.

Hydrostatic Penetration Testing of Protective Glove Materials Using Water and Synthetic Blood to Evaluate Hole Size and Screen Mesh Using an Automated Pressure Delivery System.

There are several international standards that address the resistance of chemical protective clothing materials to the penetration by liquids. The hydrostatic pressure has been documented to discriminate between protective clothing material performance and correlates with visual penetration results that are obtained with human factors validation. The same methodology, based on hydrostatic pressure equipment, is referenced also in other standards addressing penetration resistance of protective clothing and glove materials against synthetic blood or blood-borne pathogens. In this study, we present an automated hydrostatic penetration testing that integrates testing procedures from several standards to evaluate the resistance of materials to penetration by liquids under pressure. The automated control system allows the user to select a specific test method and automatically sets a stepped pressurization protocol to test the material. A pass or a fail result is produced at a certain time and pressure. As an example of application, the penetration of synthetic blood was assessed through gloves made from different materials with ISO 16603, method B, one of the five possible penetration methods and protocols available in the test equipment. The results indicate that the developed system facilitates the application of test methods used to evaluate the barrier effectiveness against liquids of materials used for protective clothing and gloves and show up that the characteristics of the retention grid used have a decisive influence on the test results. In some of the tested glove materials, holes were intentionally performed with needles with different gauges. The capacity of pinhole detection in gloves was evaluated according to the test method selected and compared with results obtained with the classic water leak test method for gloves described in EN ISO 374-2.

НЕРУЙНІВНІ МЕТОДИ КОНТРОЛЮ ПРОЦЕСІВ ТУЖАВЛЕННЯ І ТВЕРДІННЯ БУДІВЕЛЬНИХ КОМПОЗИЦІЙНИХ МАТЕРІАЛІВ ІЗ КРУПНИМ НАПОВНЮВАЧЕМ

The article deals with the problem of non-destructive control of the processes of setting and hardening of composite materials, for which coarse filler granules or mixtures of fillers of different granulometric composition are used. Since the use of standardized penetration methods in the cases under consideration becomes impossible, it is possible to draw conclusions about the stages of the processes of structure formation of a composite binder dough only by indirect signs. In such a study, methods are preferable that least disturb the structure of the hardening composite, up to non-contact ones. The article provides a comparative description of several such methods. Two of them are based on the measurement of electrical responses associ-ated with structure formation, the other two are based on the study of exothermic processes and, accordingly, the propagation velocity of ultrasonic pulses in a hardening binder dough. For a typical sample of the studied material, the time dependences of the corresponding physical characteristics are constructed. Qualitative changes in the course of these curves are comparedwith the boundaries of the stages of the structure formation process. The main qualitative changes in the time dependences of physical properties are interpreted from the standpoint of structural transformations occurring in the material. The measure-ment results are considered both from a theoretical standpoint, related to the interpretation of changes in the structure and properties of the hardening binder dough, and from an applied standpoint, focused on determining the setting time of the material, which is important for the technology of its application. Changes in physical characteristics are reduced to a single scale, which improves the accuracy of determining the setting time. It is shown that the main method, adequate to the problemunder consideration, is conveniently taken to be ultrasonic, which makes it possible to effectively display both the beginning and the end of setting. The remaining methods seem to be complementary, allowing a more thorough study of the processes during the completion of the setting. The considered research methods are also applicable to conventional materials, and some of them, with minimal modification, to hardening samples and products in the practice of building production.

Microleakage Assessment of Composite Restorations in Class V Cavities by Using Different Techniques – An In Vitro Study

Background Till date no restorative material has the capability to completely bond to the tooth structure without forming marginal gaps. This article describes about different restorative techniques in placing composite to reduce polymerization shrinkage.Aims and objectives The purpose of this study was to compare and evaluate microleakage of Class V cavities restored with two different techniques using dye penetration method and to determine better technique for placing composites which can increase the longevity of restoration by minimizing polymerization shrinkage.Methods Thirty extracted human premolar teeth were selected and Class V cavities were prepared. They were then randomly divided into two groups Group A- Snow plow technique and Group B- Control group. Composite restorations were done using two different techniques. All the samples were thermocycled and subjected to cyclic loading. Nail polish varnish was applied were immersed in dye for 24 hours and were sectioned buccolingually into two halves. The sectioned samples were subjected to stereomicroscopic investigation and depth of dye penetration was analysed according to scoring system. Statistical analysis using Statistical Package for Social Science SPSS software was done.Results No statistical variance was found in the microleakage scores between Group A and Group B and between the two techniques followed for restoration. Conclusion Placement of thin film of flowable composite under main bulk fill composite in Class V cavities did not decrease the microleakage rates resulting in decreased longevity of restorations

Spark-Based Network Security Honeypot System: Detailed Performance Analysis

In the contemporary world, network security has been of the biggest importance and acute worry in both individual and institutional wisdom, concurrent with the newly emerging technologies. Firewalls, encryption techniques, intrusion detection systems, and honeypots are just a few of the systems and technologies that have been developed to ensure information security. Systems for safeguarding an organizational environment through various defensive strategies are traditionally developed. "The enemy continues on attacking" is a primarily defensive statement. By empowering an organization to take action, Honeypot demonstrates its importance. An institution can discover, gather, address, and absorb new security policy flaws with the aid of honeypots. This methodology allows an organization's security measures to continuously incorporate new threats and penetration methods. This is the main justification of creating, developing, and using a honeypot. It is a resource that is meant to be taken advantage of and compromised. To evaluate the methodology, a spark-based honeypot strategy has been designed, put into practice, and tested in this study. The suggested study strategy has undergone many days of testing on a campus-based network. The designed system's primary function is to behave as a fully resourced computer or vault to draw intruders with the requirement that they not defend against or respond to intrusions. The studies were carried out using a number of parameters that were designed.

Leak test for solid oxide fuel cells and solid oxide electrolysis cells

A simple, fast, and economical alcohol penetration method for assessing the solid oxide cell to metal window frame seal in a typical planar design is presented. An alcohol such as ethanol or isopropanol is placed into the cavity of a cell sealed to the window frame. Within 3–5 min, one can determine if the glass seal is hermetic by visual observation along the seal edges on the side of the sealed frame. Cross bubbling and open circuit voltage methods for determining whether the seal failed or cracked at high temperature after final stack firing are also discussed.

Bacterial Leakage Evaluation of Three Root Canal Sealers with Two Obturation Techniques: An in Vitro Study

Background: The purpose of this study was to compare the quality of the coronal seal of three root canal sealers and two obturation techniques using the bacterial penetration method. Methods and Results: A total of 132 single-rooted human teeth with fully developed apices were used. The teeth were randomly assigned to three experimental groups according to the endodontic sealer used. Group 1: Samples (n=44) were obturated using a zinc oxide eugenol-based sealer, Pulp Canal Sealer EWT. Group 2: Samples (n=44) were obturated using an epoxy resin-based sealer, AH Plus. Group 3: Samples (n=44) were obturated using a bioceramic-based root canal sealer, Well-Root ST. Each group was subdivided into 2 equal subgroups in accordance with the obturation technique being used: CLCT and ThOT. Thus, 6 subgroups were formed: Sub-1A: Pulp Canal Sealer/CLCT; Sub-2A: AH Plus/CLCT; Sub-3A: Well-ROOT ST/CLCT; Sub-1B: Pulp Canal Sealer/ThOT; Sub-2B: Ah Plus/ThOT; Sub-3B: Well-ROOT ST/ThOT. A dual-chamber device was used to evaluate bacterial leakage. Fresh medium and E. faecalis were added to the upper chamber every 4 days. The broth was monitored for color change daily for 33 days. Significant differences were found among Sub-2A vs. Sub-1B (P=0.023), Sub-1A vs. Sub-3A (P=0.014), Sub-1A vs. Sub-2B (P=0.024), Sub-1A vs. Sub-3B (P=0.002), Sub-3A vs. Sub-1B (P=0.003), Sub-2B vs. Sub-1B (P=0.005), and Sub-1B vs. Sub-3B (P&lt;0.0001). There was no significant difference in the average occurrence of turbidity between CLCT and ThOT (P=0.718) Conclusion: Regardless of the obturation technique, all root canal sealers exhibited leakage; however, the bioceramic-based root canal sealer appeared to perform better than the epoxy resin-based sealer and the zinc oxide eugenol-based sealer.

A Novel Method for Testing the Effect of Base Post-Grouting of Super-Long Piles

The base post-grouting technology is widely used in pile foundation engineering to improve its behavior. For super-long piles, due to the large compression of pile shaft, conventional static load tests cannot effectively test the effect of post-grouting at the pile base. This study introduced a novel method to test the effect of base post-grouting of three 88 m long piles. A total of three test piles were grouted at the bottom of the piles. The grouting amount of the No. 1 pile was 500 kg, the No. 2 pile was 250 kg, and the No. 3 pile was 0 kg. The transmitted wave method in the pile and dynamic penetration method were used in combination to quantitatively evaluate the effect of base post-grouting on the soil below the pile base. The influencing range of base post-grouting was firstly evaluated by the transmitted wave method in the pile, and the strength of the soil before and after grouting under the same pile base was measured by the dynamic penetration method. The test results showed that: the depth of the pile base reinforcement was 2 m for No. 1 pile, and 1 m for No. 2 pile, which was consistent with the grouting amount; the elastic modulus of the soil below the pile base after base post-grouting was about twice that of the soil before base post-grouting; the strength of the soil below pile base was largely improved after grouting; and the bearing capacity of the base soil layer increased from 35.5% to 41.7% when the grouting amount increased from 250 kg to 500 kg.