Research on Examination of Construction Drawings of University Construction Projects

After completing the construction project approval, the universities will entrust a qualified design institute to carry out plan design, preliminary design and construction drawing design. Among them, the construction drawings are used to show the external shape, internal layout, detailed structure, and fixed facilities of the building, and its design depth meets the requirements for guiding construction. Construction drawings are an important basis for universities to compile bills of quantities, launch bidding, and organize construction. They are also a key factor for universities construction projects to achieve quality, investment, and schedule control goals. Therefore, the establishment of a complete construction drawing review mechanism to improve the quality of construction drawings is of great significance to the later project management.

Influence of Preparation Design and Restorative Material on Fatigue and Fracture Strength of Restored Maxillary Premolars

SUMMARY Statement of Problem: Extensive carious lesions and/or large preexisting restorations possibly contribute to crack formation, ultimately resulting in a fracture that may lead to the loss of a tooth cusp. Hence, preparation design strategy in conjunction with the restorative material selected could be influential in the occurrence of a cuspal fracture. Purpose: The purpose of this in vitro study was to evaluate the fatigue behavior and fracture strength of maxillary premolars restored with direct composite and indirect ceramic inlays and overlays, with different preparation depths in the presence or absence of cuspal coverage, and analyze their failure types. Methods and Materials: Sound maxillary premolars (N=90; n=10) were divided into nine groups: group C: control; group DCI3: direct composite inlay 3 mm; group DCI5: direct composite inlay 5 mm; group ICI3: indirect ceramic inlay 3 mm; group ICI5: indirect ceramic inlay 5 mm; group DCO3: direct composite overlay 3 mm; group DCO5: direct composite overlay 5 mm; group ICO3: indirect ceramic overlay 3 mm; group ICO5: indirect ceramic overlay 5 mm. In indirect ceramic, lithium disilicate restoration groups, immediate dentin sealing was applied. After restoration, all specimens were tested in fatigue (1,200,000 cycles, 50 N, 1.7 Hz). Samples were critically appraised, and the specimens without failure were subjected to a load to failure test. Failure types were classified and the data analyzed. Results: Zero failures were observed in the fatigue testing. The following mean load to failure strengths (N) were recorded: group ICO5: 858 N; group DCI3: 829 N; group ICO3: 816 N; group C: 804 N; group ICI3: 681 N; group DCO5: 635 N; group DCI5: 528 N; group DCO3: 507 N; group ICI5: 482 N. Zero interaction was found between design-depth-material (p=0.468). However, significant interactions were found for the design-depth (p=0.012) and design-material (p=0.006). Within restorations at preparation depth of 3 mm, direct composite overlays obtained a significantly lower fracture strength in comparison to indirect ceramic onlays (p=0.013) and direct composite inlays (p=0.028). In restorations at depth 5 mm, significantly higher fracture load values were observed in indirect ceramic overlays compared with the inlays (p=0.018). Indirect ceramic overlays on 3 mm were significantly stronger than the deep inlays in ceramic (p=0.002) and tended to be stronger than the deep direct composite inlays. Severe, nonreparable fractures were observed with preparation depth of 5 mm within ceramic groups. Conclusions: The preparation depth significantly affected the fracture strength of tooth when restored with either composite or ceramic materials. Upon deep cavity preparations, cuspal coverage proved to be beneficial when a glass ceramic was used as the restorative material. Upon shallow cavity preparations, a minimally invasive approach regarding preparation design used in conjunction with a direct composite material was favorable.

A Study on Heat Storage and Dissipation Efficiency at Permeable Road Pavements

The main contributing factor of the urban heat island (UHI) effect is caused by daytime heating. Traditional pavements in cities aggravate the UHI effect due to their heat storage and volumetric heat capacity. In order to alleviate UHI, this study aims to understand the heating and dissipating process of different types of permeable road pavements. The Ke Da Road in Pingtung County of Taiwan has a permeable pavement materials experiment zone with two different section configurations which were named as section I and section II for semi-permeable pavement and fully permeable pavement, respectively. The temperature sensors were installed during construction at the depths of the surface course (0 cm and 5 cm), base course (30 cm and 55 cm) and subgrade (70 cm) to monitor the temperature variations in the permeable road pavements. Hourly temperature and weather station data in January and June 2017 were collected for analysis. Based on these collected data, heat storage and dissipation efficiencies with respect to depth have been modelled by using multi regression for the two studied pavement types. It is found that the fully permeable pavement has higher heat storage and heat dissipation efficiencies than semi-permeable pavement in winter and summer monitoring period. By observing the regressed model, it is found that the slope of the model lines are almost flat after the depth of 30 cm. Thus, from the view point of UHI, one can conclude that the reasonable design depth of permeable road pavement could be 30 cm.

Numerical Assessment of Squeezed Branch Pile in Silty Clay Soil

Squeezed Branch Pile is derived on the basis of caste in place concrete pile. It has one or more branches along the pile shaft at design depth. Squeezed branch piles are often used in high rise building, transmission tower and in other pile foundations where anticipated uplift or vertical load may cause failure. This pile is one of the excellent options of pile foundation for soft soil and silty soil. The behaviour of Squeezed Branch pile is difficult to explain using simple pile-soil theories or two dimensional numerical analyses because of complicated geometry of pile.In the present numerical analysis, a 3D pile-soil model of conventional circular pile and squeezed branch pile foundations are analysed using MIDAS GTS NX finite element software to find out effectiveness of squeezed branch pile over conventional pile. The aim is to study the performance of Squeezed Branch Pile foundation in silty clay with respect to various parameters such as types of loading, branch diameter, branch spacing and number of branches. Analysis shows that the squeezed branch pile has higher vertical, lateral and uplift load capacity as compared to conventional pile.

Estimating Errors in Sizing LID Device and Overflow Prediction Using the Intensity-Duration-Frequency Method

Low impact development (LID) devices or green infrastructures have been advocated for urban stormwater management worldwide. Currently, the design and evaluation of LID devices adopt the Intensity-Duration-Frequency (IDF) method, which employs the average rainfall intensity. However, due to variations of rainfall intensity during a storm event, using average rainfall intensity may generate certain errors when designing a LID device. This paper presents an analytical study to calculate the magnitude of such errors with respect to LID device design and associated device performance evaluation. The normal distribution rainfall (NDR) with different standard deviations was employed to represent realistic rainfall processes. Compared with NDR method, the error in sizing the LID device was determined using the IDF method. Moreover, the overflow difference calculated using the IDF method was evaluated. We employed a programmed hydrological model to simulate different design scenarios. Using storm data from 31 regions with different climatic conditions in continental China, the results showed that different rainfall distributions (as represented by standard deviations (σ) of 5, 3, and 2) have little influence on the design depth of LID devices in most regions. The relative difference in design depth using IDF method was less than 1.00% in humid areas, −0.61% to 3.97% in semi-humid areas, and the significant error was 46.13% in arid areas. The maximum absolute difference in design depth resulting from the IDF method was 2.8 cm. For a LID device designed for storms with a 2-year recurrence interval, when meeting for the 5-year storm, the relative differences in calculated overflow volume using IDF method ranged from 19.8% to 95.3%, while those for the 20-year storm ranged from 7.4% to 40.5%. The average relative difference of the estimated overflow volume was 29.9% under a 5-year storm, and 12.0% under a 20-year storm. The relative difference in calculated overflow volumes using IDF method showed a decreasing tendency from northwest to southeast. Findings from this study suggest that the existing IDF method is adequate for use in sizing LID devices when the design storm is not usually very intense. However, accurate rainfall process data are required to estimate the overflow volume under large storms.

Dmitri Braginsky. Shostakovich and Football: Escape to Freedom

В рецензии рассматривается перевод на английский язык монографии Д. Ю. Брагинского «Шостакович и футбол: территория свободы», вышедшей в 2018 году в Москве под названием «Shostakovich and Football: Escape to Freedom». Автор рецензии делает вывод, что уникальность книги определяется сочетанием глубины замысла с необычностью и занимательностью изложения, при которой архивная точность всех фактов представлена увлекательно и динамично. Особо отмечается ценность подобранного иллюстративного материала. The review deals with the English translation of the Dmitri Braginsky monograph, published in 2018 in Moscow and entitled “Shostakovich and Football: Escape to Freedom”. The author of the review concludes that the uniqueness of the book main idea is determined by a combination of a design depth with a singularity and fascination of presentation, in which an archive precision of all the facts had put up pretty entertaining and dynamic. The high value of the selected illustrative material is noted. Keywords: Shostakovich, football, “The Golden Age” ballet, Ensemble of Song and Dance of the NKVD, the year 1936.

Finite-Difference Numerical Simulation of Dewatering System in a Large Deep Foundation Pit at Taunsa Barrage, Pakistan

This study investigates a large deep foundation pit of a hydraulic structure rehabilitation program across the Indus river, in the Punjab province of Pakistan. The total area of the construction site was 195,040 m2. Two methods, constant head permeability test and Kozeny–Carman equation, were used to determine the hydraulic conductivity of riverbed strata, and numerical simulations using the three-dimensional finite-difference method were carried out. The simulations first used hydraulic conductivity parameters obtained by laboratory tests, which were revised during model calibration. Subsequently, the calibrated model was simulated by different aquifer hydraulic conductivity values to analyze its impact on the dewatering system. The hydraulic barrier function of an underground diaphragm wall was evaluated at five different depths: 0, 3, 6, 9, and 18 m below the riverbed level. The model results indicated that the aquifer drawdown decreases with the increase in depth of the underground diaphragm wall. An optimal design depth for the design of the dewatering system may be attained when it increases to 9 m below the riverbed level.

Window Seat Weight Reduction Exploration With Nontraditional Seat Geometry

This article provides an overview of the design and exploratory testing of a nontraditional submersible window seat design. Typically, window seat geometry is guided by the American Society of Mechanical Engineers-Pressure Vessels for Human Occupancy-1 (ASME-PVHO-1) engineering standard as well as other references by ASME, Stachiw, etc. As viewing area increases, window seat geometry is partly driven by the size of the acrylic window and not solely by the requirements for a hull penetration of equivalent size. The discrepancy in strength and stiffness between the submersible hull materials and acrylic window can result in a window seat that is overbuilt relative to the required hull integrity. This research focuses on nontraditional window seat geometries that decrease weight while performing comparably to designs that conform to the ASME-PVHO-1 standard. A novel window seat is proposed with reductions in window seat weight between 22% and 33%. Design methodology, assumptions, Fine Element Analysis (FEA) results, deviations from the standard, and empirical design studies are summarized in detail. Two scale model windows were tested to their design depth for 102 cycles and showed acceptable signs of wear. FEA constraints were validated using strain gauge and displacement measurements on the conical and low pressure faces of the windows. Short Term Critical Pressure (STCP) testing was conducted in a hydrostatic pressure chamber where the two model windows reached 79% and 86% of their design pressure.