Advanced finite element analysis of a complex deep excavation case history in Shanghai

The construction of the North Square Shopping Center of the Shanghai South Railway Station is a large scale complex top-down deep excavation project. The excavation is adjacent to several current and newly planned Metro lines, and influenced by a neighboring Exchange Station excavation. The highly irregular geometry of this excavation greatly increases the complexity in 3D Finite Element modeling. The advanced numerical modeling described in this paper includes detailed structural and geotechnical behavior. Important features are considered in the analysis, e.g., 1） the small-strain stiffness of the soil, 2） the construction joints in the diaphragm wall, 3） the shrinkage in the concrete floor slabs and beams, 4） the complex construction sequences, and 5） the shape effect of the deep excavation. The numerical results agree well with the field data, and some valuable conclusions are generated.

Rethinking Yi’an(Medical Cases)as a Tool for Narrative Medicine in China

When narrative medicine(NM)was introduced into China,traditional Chinese medicine scholars found that the core concepts advocated by NM are manifested in Chinese yi’an.But why NM echoes with ancient Chinese yi’an?How can we better integrate NM into Chinese medical practices?To answer those questions,this article first investigates how NM establishes itself as a remedy to biomedicine by taking traditional healing models including TCM as its ideal Other.Then,the narrative traditions of both case histories and yi’an are examined respectively.This article argues that NM is searching for a lost tradition of narrative case histories,but yi’an functions as a living tradition of TCM.The Parallel Chart in NM,designed as a complement to the dehumanized hospital chart,is still based on a dichotomy of science and art and a conflictual doctor-patient model.But yi’an exemplifies the holistic and humane healthcare that NM hopes to achieve.A comparison of both genres also inspired us to rethink the genre of yi’an in NM.Thus,it is concluded that yi’an should be viewed as an epistemic genre integrating individualization and generalization,a bridge linking medicine and literature.And narrative yi’an can well serve as a tool for NM in China.It is also proposed that a thick description of yi’an be encouraged to further promote a pluralistic NM in China.

The Case Against Delusional Parasitosis

The body of knowledge on delusional parasitosis incriminates ＂delusional patients＂ as having imaginary external and/or internal symptoms that feel like parasite movements, dismisses them as psychiatric cases, and confuses cause with effect. The author is critical of these arguments and believes that the symptoms of crawling and pin-pricking are genuine; just misinterpreted as parasite movements. Based on the author＇s research on over 1000 ＂delusional＂ patients since 1996 at the Parasitology Center, Inc. （PCI）, the author has established that the symptoms of crawling and pin-pricking are caused by toxicity from exposure to incompatible dental materials, implants, environmental toxins among others that alter the propagation of normal nerve impulses. The author has also observed that external parasites/organisms including springtails （Collembola）, other arthropods, bacteria, and fungi represent only opportunistic infections of skin sites compromised by the toxicity disorder involving the elimination of toxins through the skin. The author has described a new pathological disorder, Neuro-cutaneous Syndrome （NCS） primarily associated with dental toxicity to which ＂delusional parasitosis＂ and Morgellons disease cases could be assigned. The author has developed a protocol for the resolution of the symptoms of NCS cases. When followed to the letter, all symptoms of NCS, conventionally called delusional parasitosis, are invariably and irreversibly resolved; each individual＇s unique circumstances taken into account. The author is also presenting a detailed case history of an NCS patient that has recovered from her experiential personal perspective.

Road Foundation Improvement by Explosive Force

A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6,8.5 m deep was encountered. A new explosive method was developed and adopted for this project. In this method, blasting is used to remove and replace soft clay with crushed stones. Explosive charges are placed in the soil to be improved according to a certain pattern. Crushed stones are piled up behind the area where charges are installed. The explosion removes most of the soil in the exploded area and causes the pile of crushed stones to slide into the area where the soil is removed by blasting. A formular was suggested to calculate the charge weight used for improving a certain type of soil. The effectiveness of the method is evaluated using borehole exploration, plate load tests,and ground-probing radar tests.

A constrained neural network model for soil liquefaction assessment with global applicability

A constrained back propagation neural network(C-BPNN)model for standard penetration test based soil liquefaction assessment with global applicability is developed,incorporating existing knowledge for liquefaction triggering mechanism and empirical relationships.For its development and validation,a comprehensive liquefaction data set is compiled,covering more than 600 liquefaction sites from 36 earthquakes in 10 countries over 50 years with 13 complete information entries.The C-BPNN model design procedure for liquefaction assessment is established by considering appropriate constraints,input data selection,and computation and calibration procedures.Existing empirical relationships for overburden correction and fines content adjustment are shown to be able to improve the prediction success rate of the neural network model,and are thus adopted as constraints for the C-BPNN model.The effectiveness of the C-BPNN method is validated using the liquefaction data set and compared with that of several liquefaction assessment methods currently adopted in engineering practice.The C-BPNN liquefaction model is shown to have improved prediction accuracy and high global adaptability.

A simple method for evaluating liquefaction potential from shear wave velocity

The simplified procedure using shear wave velocity measurements is increasingly used to evaluate the seismic liquefaction potential of soils.This procedure is based on finding the boundary separating the liquefactionand non-liquefaction cases through the analysis of liquefaction case histories,following the general format of the Seed-Idriss simplified procedure based on standard penetration test(SPT)data.It is noted that many assumptions have been made in the simplified procedure.This paper develops a simple method for evaluating the liquefaction potential of soils from shear wave velocity by using the optimum seeking method to directly analyze the liquefaction history data and quantify the influence of major factors affecting the liquefactions potential of soils.The factors considered are the earthquake magnitude,the vertical effective overburden stress,the shear wave velocity,the peak acceleration at the ground surface of the site,and the fines content of the soil.The most important factor has been identified as the shear wave velocity.The developed method uses the measured data directly and in a very simple way.Neither stress-correction of shear wave velocity nor calculation of cyclic shear stress as in the simplified procedure is required.Comparisons indicate that the developed simple method has a higher success rate for evaluating liquefaction potential of soils than the simplified procedure.A case study is presented to illustrate the application of the developed simple method and further confirms its accuracy.

Empirical evidence for estimation of subsurface settlement caused by tunneling in sand

Tunneling is vital for augmenting urban infrastructure systems in big cities.However,the ground movement or settlement induced by tunneling can cause significant damage to the surrounding buildings,bridges,roadways,pipelines,and so on.Several theoretical and empirical methods have been proposed to estimate the settlement trough at the ground surface caused by tunneling.Subsurface settlement caused by tunneling in clay has been investigated extensively to evaluate the safety of pipelines and foundations above tunnels based on the assumption of a constant volume of the settlement trough along the depth.However,subsurface settlement induced by tunneling in sand has not been understood well due to the change of volume of settlement trough along the depth.Even though an empirical method was developed by the author based on lab-scale model test results,it has not been validated using observational data from case histories.In this study,three case histories from the literature were used to verify the effectiveness of the aforementioned empirical method for estimating the subsurface settlement caused by tunneling in sand.The comparison of the calculated results and measurements from the case histories demonstrates that the empirical method is effective to predict the subsurface settlement caused by tunneling in sand.

On Evidence-Based Practice in Disaster Risk Reduction

Disaster science and scholarship are forever expanding and there are increasing calls to base disaster risk reduction policies on the evidence produced by such work.Using examples and argument,this opinion piece examines the nature of evidence.It defines evidence-based practice and considers how it has developed and become important to disaster risk reduction.A definition of what constitutes evidence is difficult to achieve but it must be made in relation to whether the data and information collected can usefully be interpreted and employed to change things for the better.Case histories from past and present centuries show that evidence can sometimes be argued over endlessly.In other cases it is roundly ignored.In yet other instances,false conclusions derived from evidence can become evidence in their own right.Nevertheless,there are situations in disaster risk reduction in which evidence is sorely needed but is clearly lacking.The effectiveness of counter-terrorism measures is one such area.In conclusion,evidence is valuable,above all if there is willingness to use it to support policy formulation,especially in a simple,transparent manner.Subjective interpretation can never be entirely removed from the use of evidence,and evidence alone will not stimulate the policy formulators to improve their decision making.