Effects of anti-pull ties on the bearing behaviors of shallow tunnel-type anchorages in soft rock

Tunnel-type anchorages(TTAs)installed in human gathering areas are characterized by a shallow burial depth,and in many instances,they utilize soft rock as the bearing stratum.However,the stability control measures and the principle of shallow TTAs in soft rock have not been fully studied.Hence,a structure suitable for improving the stability of shallow TTAs in soft rock strata,named the anti-pull tie(APT),was added to the floor of the back face.Physical tests and numerical models were established to study the influence of the APT on the load transfer of TTAs,the mechanical response of the surrounding rock,the stress distribution of the interface,and the failure model.The mechanical characteristics of APTs were also studied.The results show that the ultimate bearing capacity of TTAs with an APT is increased by approximately 11.8%,as compared to the TTAs without an APT.Also,the bearing capacity of TTAs increases approximately linearly with increasing height,width,length,and quantity of APTs,and decreases approximately linearly with increasing distance from the back face and slope angle of the tie slope.The normal squeezing between the tie slope and the surrounding rock increases the shear resistance of the interface and expands the range of the surrounding rock participating in bearing sharing.Both tension and compression zones exist in the APT during loading.The tension zone extends from the tie toe to the tie bottom along the tie slope.The range of the tie body tension zone constantly expands to the deep part of the APT with an increasing load.The peak tensile stress value is located at the tie toe.The distribution of compressive stress in the tie body is the largest at the tie top,followed by the tie slope,and then the tie bottom.

A SYMBOL OF STRONG CHINA-INDONESIA TIES

“The Jakarta-Bandung High-Speed Railway(HSR)is a crucial achievement in practical cooperation between China and Indonesia,”said Paulus Rudolf Yuniarto,a researcher at the Indonesia National Research and Innovation Agency.

Studies of Soil Physical Properties and Community Characteristics of Different Abandoned Lands in the Minqin Oasis,Downstream of the Shiyang River

[Objective] The aim was to explore physical properties and community characteristics of abandoned lands in different years in Minqin Oasis, downstream of the Shiyang River, [Method] The evolution of environment and plant community characteristics in different abandoned lands were analyzed after abandonment for 1, 2, 3, 4, 5, 8, 15, 24 and 31 years, and the plant community characteristics, water content, bulk density, porosity and mechanical composition of soil in the different a- bandoned lands were also researched in the Minqin Oasis, downstream of the Shiyang River. [Result] Plant of 32 species spread over 14 family live through fifty years appeared in abandoned lands in the study area. Shrubs was 6 species, herbs was 26 species among them, which were 18.75%, 81.25% respectively. The goose- foot family （6 species）, the composite family（4 species）,the grass family（4 species）, caltrop family（3 species） were 53.13% among them. Within the range of 0-40 cm of different abandoned Land, the soil moisture content showed a trend of first increase and then decrease with the increase of soil depth changes in soil bulk density and porosity of less obvious. In the range of 0-40 cm soil depth, the largest proportion of fine sand, followed by silt and clay and the smallest proportion of coarse sand in every plot, but the proportion of the each silt size varies little with the years aban- doned. [Conclusion] The research provides references for vegetation reconstruction and eco-environment construction in abandoned lands in downstream of Shiyang River.

Measurement of vibration frequencies of ties in masonry arches by means of a robotic total station

Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is described.The instrument made continuous recordings(up to ten per second)of the three-dimensional positions of a reflector situated at 1/2 or 1/4 of the length of the tie during vertical oscillation induced by an impulsive load.The recording slips,vibration amplitudes(and their accuracy),hourly diagram and experimental spectra of vibrations,and the corresponding frequencies were calculated.The results were verified by comparing them with the vibration frequencies and indirectly the tension and fixed support constraint calculated from accelerometric measurements.The study provides interesting information on the accuracies of the reflector′s three-dimensional coordinates,but highlighted certain limits in the application of robotized total stations for measuring vibration frequencies of ties in masonry arches.

Extension of Switching Costs Antecedents Based on Customers＇ Social Ties

The effects of customers' social ties on switching costs have recently attracted researchers' attention.This study formally included customers' social ties as a new antecedent to supplement those elucidated by Burnham in 2003.Through empirical research,this study successfully verified the reliability and validity of items created to measure social ties,and it demonstrated the facilitating effects of social ties as an antecedent on customers' procedural and relational switching costs.Finally,the study lists managerial implications aimed at retaining customers through knowledge of this added antecedent.

Ponder over the Changes in Sino-Russian-U. S. Ties

Some changes have indeed taken place in international situation from September 11 to Iraq war. Changes in big power relations in particular have given food for thought. Today Ⅰ would like to focus on the changes in the relations among China, Russia and the United States as well as my consideration of China’s diplomacy.

The Lagging behind Security Ties and the Way out

The present Sino-Japanese relations have developed smoothly and achieved marked results, but some problems are yet to be, solved. One of them is that, compared with the closer economic ties, political and security relations between the two states are lagging behind, in which security relations in particular have obstructed the deepening of ties between the two nations. As two major powers in East Asia, the ties be-

The US Enhancing Ties with Sri Lanka: Motivations and Restraints

The rapid growth in US-Sri Lanka relations is the latest attempt by the US to implement its Indo-Pacific strategy in South Asia. As the strategy materializes, the intensified US involvement in the region will bring new variables to the security situation in the Bay of Bengal and the Indian Ocean.

Chinese,Portuguese Leaders Exchange Congratulations on 40th Anniversary of Diplomatic Ties

Chinese President Xi Jinping and Portuguese President Marcelo Rebelo de Sousa on February 8 exchanged congratulations on the 40th anniversary of the establishment of China-Portugal diplomatic relations.

China's WTO Entry Helps Sino-US Ties

China applied for restoration of its status as the GATT founding member in1986. The country has made great endeavor in reducing customs duties, removing non-tariff barriers, enhancing protection of intellectual property rights andservice trades, launching reform of the foreign trade regime, eliminating trade bar-riers and improving environment for foreign investment. Over the past 14 years,China has taken part in 26 relevant multilateral meetings and hundreds of bilateralnegotiations.

A WISE STRATEGIC DECISION——Written in Celebration of Establishment of China-South Africa Diplomatic Ties

South Africa is to establish diplomatic relations with the People’s Republic ofChina by the end of this year while cutting off its official ties with Taiwan.This will be a major event worthy of warm celebrations. It will usher in a newstage in the annals of bilateral relations of friendship and cooperation. The decisionfor the changeover in diplomatic recognition by the new South Africa Governmentis a wise, crucial strategic action taken after all-round deliberations on its long-termstate interests and carried out in accordance with diplomatic norms accepted in theinternational community. No doubt, it will exert positive impact worldwide.

Xi Meets European Leaders on Advancing Ties, Global Governance

Chinese President Xi Jinping, French President Emmanuel Macron, German Chancellor Angela Merkel and European Commission President Jean- Claude Juncker met in Paris on March 26 and agreed to strengthen China-European Union (EU) relations and global governance cooperation.

Post-Sept. -11 Sino-U. S. Ties

Like a big rock thrown into the pond of current international power configuration, the event of September 11 revealed the turbulent undercurrents beneath its seemingly tranquil surface. The splashdown effect has spread beyond the United States to reach every corner of our planet. It has triggered realignment in big power relations and will have its far-

The Sign Test with Ties Included

The sign rank test is taught in virtually all introductory Statistics classes. When teaching the sign rank test the students are told to ignore the ties. Ignoring ties that support the null hypothesis is not logical. Why should valid data that support the null hypothesis be ignored? The approach taken here demonstrates a method for testing with ties included. A typical problem presentation in a text book would indicate that if you had ten ties in a sample of size fifty the tie scores would be excluded. However, the ten tie scores are a very valuable piece of statistical information which should not be ignored. The method demonstrated here shows that a different conclusion is reached in some cases when the ties are not excluded. Further many sign tests often will have ties because in some cases the data are not a cardinal number, but an ordinal number chosen from a set often results in ties. The alternative approach uses a one-tailed distribution and considers both +’s and -'s separated. A two-tailed test for equal variances is done with a one-tail of an F distribution. This alternate approach to the sign test allows the use of important statistical information which has been ignored with the traditional sign rank test.

Paving the Way for Sino-Foreign Economic and Trade Ties——Notes on Second Session of CCPIT Second Council

The China Council for the Promotion of International Trade (CCPIT) held the Second Session of the Second Council of its National Congress in the latter half of July. Attending the session were officials in charge of foreign economic relations and trade from related Chinese ministries, provinces, municipalities and autonomous regions, chairmen of 46 local and 14 industrial sub-councils throughout

Following the Tide to the Future in Commemoration of the 30th Anniversary of Sino-Japan Ties

There were both good times and bad times in the history of SinoJapanese relations.And the single most important lesson we could draw from it is that cooperation 1eads to a in-win situation,while conflict lose-lose.The purpose of reviewing and contemplating on this part of history is to look forward to the future.